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THE  ANDES  OF  SOUTHERN 

PERU 


GEOGRAPHICAL  RECONNAISSANCE  ALONG  THE 
SEVENTY-THIllD   MERIDIAN 


BY 


ISAIAH  BOWMAN 

Director  of  the  American  Geographical  Society 


PUBLISHED  FOR 

THE  AMERICAN  GEOGRAPHICAL  SOCIETY 

OF  NEW  YORK 

BY 
HENRY  HOLT  AND  COMPANY 

«.-..  /"^        1916 


f 


30944 


COPTKIOHT,    1916 
BY 

HENRY   HOLT   AND   COMPANY 


Gib  5  7 


\  G  5 


^nT' 


TO 
C.   G.  B. 


> 


PREFACE 

The  geographic  work  of  the  Yale  Peruvian  Expedition  of  1911 
was  essentially  a  reconnaissance  of  the  Peruvian  Andes  along  the 
73rd  meridian.    The  route  led  from  the  tropical  plains  of  the  lower 
Urubamba  southward  over  lofty  snow-covered  passes  to  the  desert 
coast  at  Camana.    The  strong  climatic  and  topographic  contrasts 
and  the  varied  human  life  which  the  region  contains  are  of  geo- 
graphic interest  chiefly  because  they  present  so  many  and  such 
clear    cases    of    environmental    control    within    short    distances. 
Though  we  speak  of  "isolated"  mountain  communities  in  the 
Andes,  it  is  only  in  a  relative  sense.    The  extreme  isolation  felt 
in  some  of  the  world's  great  deserts  is  here  unknown.    It  is  there- 
fore all  the  more  remarkable  when  we  come  upon  differences  of 
V  customs  and  character  in  Peru  to  find  them  strongly  developed  in 
(js^    spite  of  the  small  distances  that  separate  unlike  groups  of  people. 
^*  My  division  of  the  Expedition  undertook  to  make  a  contour  map 

>^    of  the   two-hundred-mile   stretch   of  mountain   country  between 
^^    Abancay  and  the  Pacific  coast,  and  a  great  deal  of  detailed  geo- 
'S     graphic  and  physiographic  work  had  to  be  sacrificed  to  insure  the 
completion  of  the  survey.    Camp  sites,  forage,  water,  and,  above 
J^all,  strong  beasts  for  the  topographer's  difficult  and  excessively 
^    lofty  stations  brought  daily  problems  that  were  always  serious 
^^    and  sometimes  critical.    I  was  so  deeply  interested  in  the  progress 
;     of  the  topographic  map  that  whenever  it  came  to  a  choice  of  plans 
f\    the  map  and  not  the  geography  was  first  considered.    The  effect 
upon  my  work  was  to  distribute  it  with  little  regard  to  the  de- 
mands of  the  problems,  but  I  cannot  regret  this  in  view  of  the 
great  value  of  the  maps.    Mr.  Kai  Hendriksen  did  splendid  work 
in  putting  through  two  hundred  miles  of  plane-tabling  in  two 
months  under  conditions  of  extreme  difficulty.    Many  of  his  tri- 
angulation  stations  ranged  in  elevation  from  14,000  to  nearly 


viii  PREFACE 

18,000  feet,  and  the  cold  and  storms— especially  the  hailstorms  of 
mid-afternoon — were  at  times  most  severe. 

It  is  also  a  pleasure  to  say  that  Mr.  Paul  Baxter  Lanius,  my 
assistant  on  the  lower  Urubamba  journey,  rendered  an  invaluable 
ser\"ice  in  securing  continuous  weather  records  at  Yavero  and  else- 
where, and  in  getting  food  and  men  to  the  river  party  at  a  critical 
time.  Dr.  "W.  G.  Erving,  surgeon  of  the  Expedition,  accompanied 
me  on  a  canoe  journey  through  the  lower  gorge  of  the  Urubamba 
between  Rosalina  and  the  mouth  of  the  Timpia,  and  again  by  pack 
train  from  Santa  Ana  to  Cptahuasi.  For  a  time  he  assisted  the 
topographer.  It  is  due  to  his  prompt  surgical  assistance  to  vari- 
ous members  of  the  party  that  the  field  work  was  uninterrupted. 
He  was  especially  useful  when  two  of  our  river  Indians  from 
Pongo  de  Mainique  were  accidentally  shot.  I  have  since  been  in- 
formed by  their  patron  that  they  were  at  work  within  a  few 
months. 

It  is  difficult  to  express  the  gratitude  I  feel  toward  Professor 
Hiram  Bingham,  Director  of  the  Expedition,  first  for  the  execu- 
tive care  he  displayed  in  the  organization  of  the  expedition's 
plans,  which  left  the  various  members  largely  care-free,  and  sec- 
ond, for  generously  supplying  the  time  of  various  assistants  in  the 
preparation  of  results.  I  have  enjoyed  so  many  facilities  for  the 
completion  of  the  work  that  at  least  a  year's  time  has  been  saved 
thereby.  Professor  Bingham's  enthusiasm  for  pioneer  field  work 
was  in  the  highest  degree  stimulating  to  every  member  of  the 
party.  Furthermore,  it  led  to  a  determination  to  complete  at  all 
hazards  the  original  plans. 

Finally,  T  wish  gi-atofuUy  to  acknowledge  the  expert  assistance 
of  Miss  CJladys  M.  Wrigley,  of  the  editorial  staff  of  the  American 
Geographical  Society,  who  prepared  the  climatic  tables,  many  of 
the  miscellaneous  data  related  thereto,  and  all  of  the  curves  in 
Chapter  X.  Miss  Wrigley  also  assisted  in  the  revision  of  Chap- 
ters TX  and  X  and  in  llie  correction  of  the  proof.  Tier  eager  and 
in  the  highr-st  d^greo  f;ii1hfnl  assistance  in  these  tasks  bespeaks 
a  true  scientific  spirit. 

IsATATi  Bowman. 


SPECIAL  ACKNOWLEDGMENTS  FOR  ILLUSTRATIONS 

Fig.  28.  Photograpli  by  H.  L.  Tucker,  Engineer,  Yale  Peruvian  Expedi- 
tion of  1911. 

Fig.  43.  Photograpli  by  H.  L.  Tucker. 

Fig.  44.  Photograph  by  Professor  Hiram  Bingham. 

Figs.  136,  139,  140.  Data  for^  hachured  sketch  maps,  chiefly  from  topo- 
graphic] sheets  by  A.  H.  Bumstead,  Topographer  to  Professor  Bingham's 
Peruvian  Expeditions  of  1912  and  1914. 


CONTENTS 


PART  I 

HUMAN  GEOGRAPHY 


CHAPTEU 
I. 
11. 
III. 

V. 
VI. 

(vrp 

VIII. 

IX. 

X. 


The  Regions  of  Peru 

The  Rapids  and  Canyons  of  the  Urubamba  . 
The  Rubber  Forests     .       .       .       . 

The  Forest  IndiIns 

The  Country  of  the  Shepherds 
The  Border  Valleys  of  the  Eastern  Andes  . 
The   Geographio  Basis   of   Revolutions   and   of   Human 
Character  in  the  Peruvian  Andes 

The  Coastal  Desert 

Climatology  of  the  Peruvian  Andes 
Meteorological  Records  from  the  Peruvian  Andes 


PAGE 

1 
8 
22 
36 
46 
68 


110 
121 
157 


PART  II 

PHYSIOGRAPHY  OF  THE  PERUVIAN  ANDES 

XI.     The  Peruvian  Landscape 183 

XII.     The  Western  Andes:  The  Maritime  Cordillera  or  Cor- 
dillera Occidental 199 

XIII.  The  Eastern  Andes:  The  Cordillera  Vilcapampa      .       .  204 

XIV.  The  Coastal  Terraces 225 

XV.     Physiographic  and  Geologic  Development     ....  233 

XVI.     Glacial  Features 274 

Appendix  A.     Survey  Methods  Employed  in  the  Construction  of 

the  Seven  Accompanying  Topographic  Sheets    .  315 

Appendix  B,     Fossil  Determinations 321 

Appendix  C.     Key  to  Place  Names 324 

Index 327 

TOPOGRAPHIC  SHEETS 

Camana  Quadrangle 114 


Aplao 
Coropuna 
Cotahuasi 
La  Cumbi'e 
Antabamla 
Lambrarri'  l 


120 
188 
192 
202 
282 
304 


PART    I 
HUMAN    GEOGRAPHY 

CHAPTER  I 

THE  REGIONS  OF  PERU 

Let  four  Peruvians  begin  this  book  by  telling  what  manner  of 
country  they  live  in.  Their  ideas  are  provincial  and  they  have  a 
fondness  for  exaggerated  description:  but,  for  all  that,  they  will 
reveal  much  that  is  true  because  they  will  at  least  reveal  them- 
selves. Their  opinions  reflect  both  the  spirit  of  the  toiler  on  the 
land  and  the  outlook  of  the  merchant  in  the  town  in  relation  to 
geography  and  national  problems.  Their  names  do  not  matter; 
let  them  stand  for  the  four  human  regions  of  Peru,  for  they  are 
in  many  respects  typical  men. 

The  Fokest  Dweller 

One  of  them  I  met  at  a  rubber  station  on  the  lower  Urubamba 
River.^  He  helped  secure  my  canoe,  escorted  me  hospitably  to  his 
hut,  set  food  and  drink  before  me,  and  talked  of  the  tropical  forest, 
the  rubber  business,  the  Indians,  the  rivers,  and  the  trails.  In  his 
opinion  Peru  was  a  land  of  great  forest  resources.  Moreover, 
the  fertile  plains  along  the  river  margins  might  become  the  sites 
of  rich  plantations.  The  rivers  had  many  fish  and  his  garden 
needed  only  a  little  cultivation  to  produce  an  abundance  of  food. 
Fruit  trees  grew  on  every  hand.  He  had  recently  married  the 
daughter  of  an  Indian  chief. 

Formerly  he  had  been  a  missionary  at  a  rubber  station  on  the 
Madre  de  Dios,  where  the  life  was  hard  and  narrow,  and  he  doubted 
if  there  were  any  real  converts.  Himself  the  son  of  an  English- 
man and  a  Chilean  woman,  he  found,  so  he  said,  that  a  mission- 
ary's life  in  the  rubber  forest  was  intolerable  for  more  than  a  few 

*  For  all  locations  mentioned  see  maps  accompanying  the  text  or  Appendix  C. 


2  THE  ANDES  OF  SOUTHERN  PERU 

years.  Yet  he  had  no  fault  to  find  with  the  religious  system  of 
which  he  had  once  formed  a  part;  in  fact  he  had  still  a  certain 
curious  mixed  loyalty  to  it.  Before  I  left  he  gave  me  a  photo- 
graph of  himself  and  said  with  little  pride  and  more  sadness  that 
perhaps  I  would  remember  him  as  a  man  that  had  done  some  good 
in  the  world  along*  with  much  that  might  have  been  better. 

We  shall  understand  our  interpreter  better  if  we  know  who 
his  associates  were.  He  lived  with  a  Frenchman  who  had  spent 
several  years  in  Africa  as  a  soldier  in  the  ' '  Foreign  Legion. ' '  If 
you  do  not  know  what  that  means,  you  have  yet  all  the  pleasure 
of  an  interesting  discovery.  The  Frenchman  had  reached  the  sta- 
tion the  year  before  quite  destitute  and  clad  only  in  a  shirt  and 
a  pair  of  trousers.  A  day's  journey  north  lived  a  young  half- 
breed — son  of  a  drunken  father  and  a  Machiganga  woman,  who 
cheated  me  so  badly  when  I  engaged  Indian  paddlers  that  I  should 
almost  have  preferred  that  he  had  robbed  me.  Yet  in  a  sense  he 
had  my  life  in  his  hands  and  I  submitted.  A  German  and  a  native 
Peruvian  ran  a  rubber  station  on  a  tributary  two  days'  journey 
from  the  first.  It  will  be  observed  that  the  company  was  mixed. 
They  were  all  Peruvians,  but  of  a  sort  not  found  in  such  relative 
abundance  elsewhere.  The  defeated  and  the  outcast,  as  well  as 
the  pioneer,  go  down  eventually  to  the  hot  forested  lands  where 
men  are  forgotten. 

While  he  saw  gold  in  every  square  mile  of  his  forested  region, 
my  clerical  friend  saw  misery  also.  The  brutal  treatment  of  the 
Indians  by  the  whites  of  the  Madre  de  Dios  country  he  could  speak 
of  only  as  a  man  reviving  a  painful  memory.  The  Indians  at  the 
station  loved  him  devotedly.  There  was  only  justice  and  kind- 
ness in  all  his  dealings.  Because  he  had  large  interests  to  look 
after,  he  knew  all  the  members  of  the  tribe,  and  his  word  was  law 
in  no  hackneyed  sense.  A  kindlier  man  never  lived  in  the  rubber 
forest.  His  influence  as  a  high-souled  man  of  business  was  vastly 
greater  than  as  a  missionary  in  this  frontier  society.  He  could 
daily  illustrate  by  practical  example  what  he  had  formerly  been 
able  only  to  fjroaoh. 

He  thought  the  life  of  tho  Peruvian  cities   debasing.     The 


Fig.  1. 


r-'' 


Fig. 


Fig.  1 — Tropical  vegetation,  clearing  on  the  river  bank  and  rubber  station  at 
Pongo  de  ilainicjue.  The  pronounced  scarp  on  the  northeastern  border  of  the  Andes 
is  seen  in  the  right  background. 

Fig.  2 — Pushing  a  heavy  dugout  against  the  current  in  the  rapids  below  Pongo  de 
Mainique.     The  Indian  boj-  and  his  father  in  the  canoe  had  been  accidentally  shot. 


In;.  .'!  I'roMi  ice  to  Mii^.ir  fane,  I  riil(iiiiil);i  Xalltv.  at  (*'()l|miii.  On  tlic  north- 
enHtfrn  Ifordi-r  nf  the  Cordillcrii  Vilcapampa  looking;  iii)strcaiii.  In  (lie  cxlrcmo  back- 
grouriil  and  tliirtrr-n  mIxU-ctiUih  of  nn  inch  from  Ihr  \i>\)  of  llic  piitiirc  is  Uic  Hharp 
ppnk  f»f  Salrantiiy.  Only  tin-  lower  end  of  tin-  iimrr  (i|m  ii  pmiion  i>t  tlic  Canyon  of 
Tonuitoy  in  here  shown.  There  in  a  litld  of  HU^;ar  cnin'  in  tlic  fnicf^MoHiiii  and  liie 
valley  trail   \n  shown  on   liie  oppoHite  side  r)f   (In-  river. 


THE  REGIONS  OF  PERU  3 

coastal  valleys  were  small  and  dry  and  the  men  who  lived  there 
were  crowded  and  poor  (sic).  The  plateau  was  inhabited  by  In- 
dians little  better  than  brutes.  Surely  I  could  not  think  that  the 
fine  forest  Indian  was  lower  than  the  so-called  civilized  Indian  of 
the  plateau.  There  was  plenty  of  room  in  the  forest;  and  there 
was  wealth  if  you  knew  how  to  get  at  it.  Above  all  you  were  far 
from  the  annoying  officials  of  the  government,  and  therefore  could 
do  much  as  you  pleased  so  long  as  you  paid  your  duties  on  rubber 
and  did  not  wantonly  kill  too  many  Indians. 

For  all  his  kindly  tolerance  of  men  and  conditions  he  yet  found 
fault  with  the  government.  ''They"  neglected  to  build  roads,  to 
encourage  colonization,  and  to  lower  taxes  on  the  forest  products, 
which  were  always  won  at  great  risk.  Nature  had  done  her  part 
well — it  was  only  government  that  hindered.  Moreover,  the  for- 
ested region  was  the  land  of  the  future.  If  Peru  was  to  be  a  great 
nation  her  people  would  have  to  live  largely  upon  the  eastern 
plains.  Though  others  spoke  of  "going  in"  and  ''coming  out"  of 
the  rubber  country  as  one  might  speak  of  entering  and  leaving  a 
dungeon,  he  always  spoke  of  it  as  home.  Though  he  now  lived 
in  the  wilderness  he  hoped  to  see  the  day  when  plantations  cov- 
ered the  plains.  A  greater  Peru  and  the  forest  were  inseparable 
ideas  to  him. 

The  Eastern  Valley  Planter 

My  second  friend  lived  in  one  of  the  beautiful  mountain  val- 
leys of  the  eastern  Andes.  We  walked  through  his  clean  cacao 
orchards  and  cane  fields.  Like  the  man  in  the  forest,  he  believed 
in  the  thorough  inefficiency  of  the  government;  otherwise  why 
were  there  no  railways  for  the  cheaper  transportation  of  the  val- 
ley products,  no  dams  for  the  generation  of  power  and  the  storage 
of  irrigation  water,  not  even  roads  for  mule  carts  1  Had  the  gov- 
ernment been  stable  and  efficient  there  would  now  be  a  dense  popu- 
lation in  the  eastern  valleys.  Revolutions  were  the  curse  of  these 
remote  sections  of  the  country.  The  ne'er-do-wells  became  gen- 
erals. The  loafer  you  dismissed  today  might  demand  ten  thou- 
sand dollars  tomorrow  or  threaten  to  destroy  your  plantation. 


4  THE  ANDES  OF  SOUTHERN  PERU 

The  government  troops  might  come  to  help  you,  but  they  were 
always  too  late. 

For  this  one  paid  most  burdensome  taxes.  Lima  profited 
thereby,  not  the  valley  planters.  The  coast  people  were  the 
favored  of  Peru  anyhow.  They  had  railroads,  good  steamer 
service,  jDublic  improvements  at  government  expense,  and  com- 
paratively light  taxes.  If  the  government  were  impartial  the 
eastern  valleys  also  would  have  railways  and  a  dense  population. 
Who  could  tell?  Perhaps  the  capital  city  might  be  here.  Cer- 
tainly it  was  better  to  have  Lima  here  than  on  the  coast  where 
the  Chileans  might  at  any  time  take  it  again.  The  blessings  of 
the  valleys  were  both  rich  and  manifold.  Here  was  neither  a  cold 
plateau  nor  the  hot  plains,  but  fertile  valleys  with  a  vernal  climate. 

We  talked  of  much  else,  but  our  conversation  had  always  the 
pioneer  flavor.  And  though  an  old  man  he  saw  always  the  future 
Peru  growing  wonderfully  rich  and  powerful  as  men  came  to  rec- 
ognize and  use  the  resources  of  the  eastern  valleys.  This  too  was 
the  optimism  of  the  pioneer.  Once  started  on  that  subject  he  grew 
eloquent.  He  was  provincial  but  he  was  also  intensely  patriotic. 
He  never  missed  an  opportunity  to  impress  upon  his  guests  that 
a  great  state  would  arise  when  people  and  rulers  at  last  recog- 
nized the  wealth  of  eastern  Peru. 

The  Highland  Shepherd 

Tlie  people  who  live  in  the  lofty  highlands  and  mountains  of 
Peru  have  several  months  of  real  winter  weather  despite  their 
tropical  latitude.  In  the  midst  of  a  snowstorm  in  the  Maritime 
Cordillera  I  met  a  solitary  traveler  bound  for  Cotahuasi  on  the 
door  of  a  deep  canyon  a  day's  journey  toward  the  east.  It  was 
noon  and  we  halted  our  pack  trains  in  the  lee  of  a  huge  rock  shelter 
to  escape  tlie  bitter  wind  that  blew  down  from  the  snow-clad  peaks 
of  Solimana.  Men  who  follow  the  same  trails  arc  fraternal.  In 
a  moment  we  had  food  from  our  saddle-bags  spread  on  the  snow 
under  llic  coi'iicr  of  a  poncho  niid  bad  exchanged  the  best  in  each 
other's  collection  as  ii;iliir;dly  as  friends  exchange  greetings.  By 
the  time  I  had  told  him  whciicc  and  why  in  response  to  his  inevita- 


THE  REGIONS  OF  PERU  6 

ble  questions  we  had  finished  the  food  and  had  gathered  a  heap 
of  tola  bushes  for  a  fire.  The  arriero  (muleteer)  brought  water 
from  a  spring  in  the  hollow  below  us.  Though  the  snow  thick- 
ened, the  wind  fell.  We  were  comfortable,  even  at  16,000  feet, 
and  called  the  place  "The  Salamanca  Club."  Then  I  questioned 
him,  and  this  is  what  he  said: 

''I  live  in  the  deep  valley  of  Cotahuasi,  but  my  lands  lie  chiefly 
up  here  on  the  plateau.  My  family  has  held  title  to  this  puna  ever 
since  the  Wars  of  Liberation,  except  for  a  few  years  after  one  of 
our  early  revolutions.  I  travel  about  a  great  deal  looking  after 
my  flocks.  Only  Indians  live  up  here.  Away  off  yonder  beyond 
that  dark  gorge  is  a  group  of  their  huts,  and  on  the  bright  days 
of  summer  you  may  see  their  sheep,  llamas,  and  alpacas  up  here, 
for  on  the  floors  of  the  watered  valleys  that  girdle  these  volcanoes 
there  are  more  tender  grasses  than  grow  on  this  despoblado.  I 
give  them  corn  and  barley  from  my  irrigated  fields  in  the  valley ; 
they  give  me  wool  and  meat.  The  alpaca  wool  is  most  valuable. 
It  is  hard  to  get,  for  the  alpaca  requires  short  grasses  and  plenty 
of  water,  and  you  see  there  is  only  coarse  tufted  ichu  grass  about 
us,  and  there  are  no  streams.  It  is  all  right  for  llamas,  but  alpacas 
require  better  forage. 

''No  one  can  imagine  the  poverty  and  ignorance  of  these  moun- 
tain shepherds.  They  are  filthier  than  beasts.  I  have  to  watch 
them  constantly  or  they  would  sell  parts  of  the  flocks,  which 
do  not  belong  to  them,  or  try  to  exchange  the  valuable  alpaca  wool 
for  coca  leaves  in  distant  towns.    They  are  frequently  drunk." 

''But  where  do  they  get  the  drink?  "  I  asked.  "And  what  do 
you  pay  them?  " 

"Oh,  the  drink  is  chiefly  imported  alcohol,  and  also  chicha  made 
from  corn.  They  insist  on  having  it,  and  do  better  when  I  bring 
them  a  little  now  and  then.  They  get  much  more  from  the  deal- 
ers in  the  towns.  As  for  pay,  I  do  not  pay  them  anything  in 
money  except  when  they  bring  meat  to  the  valley.  Then  I  give 
them  a  few  reales  apiece  for  the  sheep  and  a  little  more  for  the 
llamas.  The  flocks  all  belong  to  me  really,  but  of  course  the  poor 
Indian  must  have  a  little  money.    Besides,  I  let  him  have  a  part 


6  THE  ANDES  OF  SOUTHERN  PERU 

of  the  yearly  increase.    It  is  not  much,  but  he  has  always  lived 
this  way  and  I  suppose  that  he  is  contented  after  a  fashion." 

Then  he  became  eager  to  tell  what  wealth  the  mountains  con- 
tained in  soil  and  climate  if  only  the  right  grasses  were  intro- 
duced by  the  government. 

"Here,  before  us,  are  vast  punas  almost  without  habitations. 
If  the  officials  would  bring  in  hardy  Siberian  grasses  these  lava- 
covered  plateaus  might  be  carpeted  with  pasture.  There  would  be 
villages  here  and  there.  The  native  Indians  easily  stand  the  alti- 
tude. This  whole  Cordillera  might  have  ten  times  as  many  people. 
Why  does  the  government  bother  about  concessions  in  the  rubber 
forests  and  roads  to  the  eastern  valleys  when  there  are  these  vast 
tracts  only  requiring  new  seeds  to  develop  into  rich  pastures? 
The  government  could  thus  greatly  increase  its  revenues  because 
there  is  a  hea^^  ^^x  on  exported  wool." 

Thus  he  talked  about  the  bleak  Cordillera  until  we  forgot  the 
pounding  of  our  hearts  and  our  frequent  gasps  for  breath  on  ac- 
count of  the  altitude.  His  rosy  picture  of  a  well-populated  high- 
land seemed  to  bring  us  dowTi  nearer  sea  level  where  normal  folks 
lived.  To  the  Indians  the  altitude  is  nothing.  It  has  an  effect,  but 
it  is  slight;  at  any  rate  they  manage  to  reproduce  their  kind  at 
elevations  that  would  kill  a  white  mother.  If  alcohol  were  abol- 
ished and  better  grasses  introduced,  these  lofty  pastures  might 
indeed  support  a  much  larger  population.  The  sheep  pastures  of 
the  world  are  rapidly  disappearing  before  the  march  of  the  farmer. 
Here,  well  above  the  limit  of  cultivation,  is  a  permanent  range^ 
one  of  the  great  as  well  as  permanent  assets  of  Peru. 

The  Coastal  Planter 

The  man  from  the  deep  Majcs  Valley  in  the  coastal  desert  rode 
out  with  me  through  cotton  fields  as  rich  and  clean  as  those  of  a 
Texas  plantation.  He  was  tall,  straight-limbed,  and  clear-eyed — 
one  of  the  energetic  younger  generation,  yet  with  the  blood  of  a 
proud  old  family.  We  forded  the  river  and  rode  on  through  vine- 
yards and  fig  orchards  loaded  with  fruit.  His  manner  became 
deeply  earnest  as  he  pictured  the  future  of  Peru,  when  her  people 


Fig.  4. 


;;:%e».«^ 


Fig.  5. 


Fig.  4 — Large  ground  moss — so-called  yareta — used  for  fuel.  It  occurs  in  the  zone 
of  Alpine  vegetation  and  is  best  developed  in  regions  where  tJie  snowline  is  highest. 
The  photograph  represents  a  typical  occurrence  between  Cotahuasi  and  Salamanca, 
elevation  16,000  feet  (4,880  m.).  The  snowline  is  here  at  17,500  feet  (.5,333  m.).  In 
the  foreground  is  the  most  widely  distributed  tola  bush,  also  used  for  fuel. 

Fig.  5 — Expedition's  camp  near  Lambrama,  15.500  feet  (4,720  m.),  after  a  snow- 
storm.    The  location  is  midway  in  the  pasture  zone. 


Flo.  C. 


W  f 


Vw.  1. 

Via.  ft — IrriK'tt"!    '  liili    Vullfv    (ui    iln-    mitHkirls    of    Arecmipn.      'Hie    lower  hIojx's 

of  Kl  MiMti  (in-  in  llu'  left  liackKruuiKl.  Tlic  Mto  dc  los  IhitNas  or  l'lii)<;ni  of  IJones 
lic'H  on   tlu-   fiirdirr   nidc   of   tlic   valh-y. 

Kio.  7 — CroHHinj;  llii'  lii^flirst  fiiinn  (ClnKniilo)  in  tlic  ('(ndilitin  \  il(;i|i:iiri|)ii,  14, 500 
feet    (4,420  m.).     (irii/,iiif{  \h  lien-  carried  on   iip  to   tlio  Hnowiiiic 


THE  REGIONS  OF  PERU  7 

would  take  advantage  of  scientific  methods  and  use  labor-saving 
machinery.  He  said  that  the  methods  now  in  use  were  medieval, 
and  he  pointed  to  a  score  of  concrete  illustrations.  Also,  here  was 
water  running  to  waste,  yet  the  desert  was  on  either  hand.  There 
should  be  dams  and  canals.  Every  drop  of  water  was  needed. 
The  population  of  the  valley  could  be  easily  doubled. 

Capital  was  lacking  but  there  was  also  lacking  energy  among 
the  people.  Slipshod  methods  brought  them  a  bare  living  and 
they  were  too  easily  contented.  Their  standards  of  life  should  be 
elevated.  Education  was  still  for  the  few,  and  it  should  be  uni- 
versal. A  new  spirit  of  progress  was  slowly  developing — a  more 
general  interest  in  public  affairs,  a  desire  to  advance  with  the 
more  progressive  nations  of  South  America, — and  when  it  had 
reached  its  culmination  there  would  be  no  happier  land  than 
coastal  Peru,  already  the  seat  of  the  densest  populations  and  the 
most  highly  cultivated  fields. 

These  four  men  have  portrayed  the  four  great  regions  of  Peru 
— the  lowland  plains,  the^  eastern  mountain  valleys,  the  lofty 
plateaus,  and  the  valley  oases  of  the  coast.  This  is  not  all  of 
Peru.  The  mountain  basins  have  their  own  peculiar  qualities  and 
the  valley  heads  of  the  coastal  zone  are  unlike  the  lower  valleys 
and  the  plateau  on  either  hand.  Yet  the  chief  characteristics  of 
the  country  are  set  forth  with  reasonable  fidelity  in  these  indi- 
vidual accounts.  Moreover  the  spirit  of  the  Peruvians  is  better 
shown  thereby  than  their  material  resources.  If  this  is  not  Peru, 
it  is  what  the  Peruvians  think  is  Peru,  and  to  a  high  degree  a 
man's  country  is  what  he  thinks  it  is — at  least  it  is  little  more  to 
him. 


CHAPTER  II 
THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA 

Among  the  scientifically  unexplored  regions  of  Peru  there  is 
no  other  so  alluring  to  the  geographer  as  the  vast  forested  realm 
on  the  eastern  border  of  the  Andes.  Thus  it  happened  that  within 
two  weeks  of  our  arrival  at  Cuzco  we  followed  the  northern  trail 
to  the  great  canyon  of  the  Urubamba  (Fig.  8),  the  gateway  to  the 
eastern  valleys  and  the  lowland  plains  of  the  Amazon.  It  is  here 
that  the  adventurous  river,  reenforced  by  hundreds  of  mountain- 
born  tributaries,  finally  cuts  its  defiant  way  through  the  last  of  its 
great  topographic  barriers.  More  than  seventy  rapids  interrupt 
its  course;  one  of  them,  at  the  mouth  of  the  Sirialo,  is  at  least  a 
half-mile  in  length,  and  long  before  one  reaches  its  head  he  hears 
its  roaring  from  beyond  the  forest-clad  mountain  spurs. 

The  great  bend  of  the  Urubamba  in  which  the  line  of  rapids 
occurs  is  one  of  the  most  curious  hydrographic  features  in  Peru. 
The  river  suddenly  changes  its  general  northward  course  and 
striking  south  of  west  flows  nearly  fifty  miles  toward  the  axis  of 
the  mountains,  where,  turning  almost  in  a  complete  circle,  it  makes 
a  final  assault  upon  the  eastern  mountain  ranges.  Fifty  miles 
farther  on  It  breaks  through  the  long  sharp-crested  chain  of  the 
Front  Range  of  the  Andes  in  a  splendid  gorge  more  than  a  half- 
mile  deep,  the  famous  Pongo  de  Mainiqiie  (Fig.  9). 

Our  chief  object  in  descending  the  line  of  rapids  was  to  study 
the  canyon  of  the  Urubamba  below  Rosalina  and  to  make  a  topo- 
graphic skotcli  map  of  it.  We  also  wislied  to  know  what  secrets 
might  ])('  gathered  in  this  liitlicrto  unexplored  stretch  of  country, 
what  people  dwelt  along  its  ])anks,  and  if  the  vague  tales  of  de- 
serted towns  and  fugitive  tribes  had  any  basis  in  fact. 

We  could  gather  almost  no  information  as  to  the  nature  of  the 
river  except  from  the  report  of  Major  Kerbey,  an  American,  who, 
in  1807,  descended  the  last  twenty  miles  of  the  one  hundred  we 
proposed  to  navigate,     lie  ))ronounced  the  journey  more  hazard- 

8 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA 


Pon;[o  de  Mainique 


ROUGH  SKETCH  CONTOURMAP 

off/ie 

URUBAMBA  VALLEY 

BETWEEN    ROSALINA 
AND  PONGO  OE  MAINIQUE 

ISAIAH   BOWMAN 

Approx  sco/e  ° iHWLS 

Con/our  interval  approximately  ZOO  feel. 
.  rapids 

alluvial  flats,  locally  called  playos 
Elevation  of  Rosalina  ■  2,000  feet 

//   Porigo  de  Mainique:  f.ZOO  feet 
„  Passes  on  trail  between  Rasali no 
and  Pongo  de  Mai  ni  que  5000-7.000  ft. 


Fig.  S — Sketch  map  showing  the  route  of  the  Yale- Peruvian  Expedition  of  1911 
down  the  Urubamba  Valley,  together  with  the  area  of  the  main  map  and  the  clianges 
in  the  delineation  of  the  bend  of  the  Urubamba  resulting  from  the  surveys  of  the 
Expedition.  Based  on  the  "  Mapa  que  comprende  las  ultimas  exploraciones  y  estudios 
verifieados  desde  1900  hasta  1906,"  1:1,000,000,  Bol.  Soc.  Geogr.  Lima,  Vol.  25,  No.  3, 
1909.  For  details  of  the  trail  from  Rosalina  to  Pongo  de  Mainique  see  "  Piano  de  las 
Secciones  y  Afluentes  del  Rio  Urubamba:  1902-1904,  scale  1:150,000  by  Luis  M. 
Robledo  in  Bol.  Soc.  Greogr.  Lima,  Vol.  25,  No.  4,  1909.  Only  the  lower  slopes  of 
the  long  mountain  spurs  can  be  seen  from  the  river;  hence  only  in  a  few  places  could 
observations  be  made  on  the  topography  of  distant  ranges.  Paced  distances  of  a  half 
mile  at  irregular  intervals  were  used  for  the  estimation  of  longer  distances.  Direc- 
tions were  taken  by  compass  corrected  for  magnetic  deviation  as  determined  on  the 
seventy -third  meridian  (See  Appendix  A).  The  position  of  Rosalina  on  Robledo's 
map  was  taken  as  a  base. 


10  THE  ANDES  OF  SOUTHERN  PERU 

ous  than  Major  Powell's  famous  descent  of  the  Grand  Canyon  in 
1867 — an  obvious  exaggeration.  He  lost  his  canoe  in  a  treacher- 
ous rapid,  was  deserted  by  his  Indian  guides,  and  only  after  a 
painful  march  through  an  all  but  impassable  jungle  was  he  finally 
able  to  escape  on  an  abandoned  raft.  Less  than  a  dozen  have 
ventured  down  since  Major  Kerbey's  day.  A  Peruvian  mining 
engineer  descended  the  river  a  few  years  ago,  and  four  Italian 
traders  a  year  later  floated  down  in  rafts  and  canoes,  losing  al- 
most all  of  their  cargo.  For  nearly  two  months  they  were 
marooned  upon  a  sand-bar  waiting  for  the  river  to  subside.  At 
last  they  succeeded  in  reaching  Mulanquiato,  an  Indian  settlement 
and  plantation  owned  by  Pereira,  near  the  entrance  to  the  last 
canyon.  Their  attempted  passage  of  the  worst  stretch  of  rapids 
resulted  in  the  loss  of  all  their  rubber  cargo,  the  work  of  a  year. 
Among  the  half  dozen  others  who  have  made  the  journey — Indians 
and  slave  traders  from  down-river  rubber  posts — there  is  no  rec- 
ord of  a  single  descent  without  the  loss  of  at  least  one  canoe. 

To  reach  the  head  of  canoe  navigation  we  made  a  two  weeks' 
muleback  journey  north  of  Cuzco  through  the  steep-walled  granite 
Canyon  of  Torontoy,  and  to  the  sugar  and  cacao  plantations  of  the 
middle  Urubamba,  or  Santa  Ana  Valley,  where  we  outfitted.  At 
Echarati,  thirty  miles  farther  on,  where  the  heat  becomes  more  in- 
tense and  the  first  patches  of  real  tropical  forest  begin,  we  were 
obliged  to  exchange  our  beasts  for  ten  fresh  animals  accustomed  to 
forest  work  and  its  privations.  Three  days  later  we  pitched  our 
tent  f)ii  Iho  rivor  bank  at  Rosalina,  the  last  outpost  of  the  valley  set- 
tlements. As  we  dropped  down  the  steep  mountain  slope  before 
striking  the  river  flood  plain,  we  passed  two  half-naked  Machi- 
ganga  Indians  perched  on  the  limbs  of  a  tree  beside  the  trail,  our 
first  sight  of  mombors  of  a  tribe  whose  territory  we  had  now  en- 
tered. Latfr  in  tiie  day  they  crossed  the  river  in  a  dugout,  landed 
on  the  sand-bar  above  ns,  jind  gathered  brush  for  the  nightly  fire, 
around  which  they  lie  wrapped  in  a  single  shirt  woven  from  the 
fiber  of  the  wild  cotton. 

Rosalina  is  luirdly  more  than  a  name  on  Ihe  map  and  a  camp 
site  on  the  river  ])ank'.    Some  distance  back  from  the  left  bank  of 


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bamlm  (  mci-  nuip,  Fif^.  H).  Tli,.  Mncliigiirij^ji  liidiiins  iihc  these  <  :uie  alielters  duriiif,'  the 
/iHhin^'  Meiixon,  wlicn  the  rivi-r  Ih  low. 

Flo.    12 — Thirty-foot  ciiiioe   in   :i    riipid   jilmve    I'oiipi  dc    Mniniiiiie. 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA        11 

the  river  is  a  sugar  plantation,  whose  owner  lives  in  the  cooler 
mountains,  a  day's  journey  away;  on  the  right  bank  is  a  small 
clearing  planted  to  sugar  cane  and  yuca,  and  on  the  edge  of  it  is 
a  reed  hut  sheltering  three  inhabitants,  the  total  population  of 
Rosalina.  The  owner  asked  our  destination,  and  to  our  reply  that 
we  should  start  in  a  few  days  for  Pongo  de  Mainique  he  offered 
two  serious  objections.  No  one  thought  of  arranging  so  difficult 
a  journey  in  less  than  a  month,  for  canoe  and  Indians  were  diffi- 
cult to  find,  and  the  river  trip  was  dangerous.  Clearly,  to  start 
without  the  loss  of  precious  time  would  require  unusual  exertion. 
We  immediately  despatched  an  Indian  messenger  to  the  owner 
of  the  small  hacienda  across  the  river  while  one  of  our  peons  car- 
ried a  second  note  to  a  priest  of  great  influence  among  the  forest 
Indians,  Padre  Mendoza,  then  at  his  other  home  in  the  distant 
mountains. 

The  answer  of  Seiior  Morales  was  his  appearance  in  person  to 
offer  the  hospitality  of  his  home  and  to  assist  us  in  securing  canoe 
and  oarsmen.  To  our  note  the  Padre,  from  his  hill-top,  sent  a 
polite  answer  and  the  offer  of  his  large  canoe  if  we  would  but 
guarantee  its  return.  His  temporary  illness  prevented  a  visit 
to  which  we  had  looked  forward  with  great  interest. 

The  morning  after  our  arrival  I  started  out  on  foot  in 
company  with  our  arriero  in  search  of  the  Machigangas,  who 
fish  and  hunt  along  the  river  bank  during  the  dry  season  and  re- 
tire to  their  hill  camps  when  the  heavy  rains  begin.  We  soon  left 
the  well-beaten  trail  and,  following  a  faint  woodland  path,  came 
to  the  river  bank  about  a  half  day's  journey  below  Rosalina. 
There  we  found  a  canoe  hidden  in  an  overhanging  arch  of  vines, 
and  crossing  the  river  met  an  Indian  family  who  gave  us  further 
directions.  Their  vague  signs  were  but  dimly  understood  and  we 
soon  found  ourselves  in  the  midst  of  a  carrizo  (reed)  swamp 
filled  with  tall  bamboo  and  cane  and  crossed  by  a  network  of  inter- 
lacing streams.  We  followed  a  faint  path  only  to  find  ourselves 
climbing  the  adjacent  mountain  slopes  away  from  our  destination. 
Once  again  in  the  swamp  we  had  literally  to  cut  our  way  through 
the  thick  cane,  wade  the  numberless  brooks,  and  follow  wild  ani- 


12  THE  ANDES  OF  SOUTHERN  PERU 

mal  trails  until,  late  in  the  day,  famished  and  thirsty,  we  came 
upon  a  little  clearing  on  a  sand-bar,  the  hut  of  La  Sama,  who 
knew  the  Machigangas  and  their  villages. 

After  our  long  day's  work  we  had  fish  and  yuca,  and  water 
to  which  had  been  added  a  little  raw  cane  sugar.  Late  at  night 
La  Sama  returned  from  a  trip  to  the  Indian  villages  down  river. 
He  brought  with  him  a  half-dozen  Machiganga  Indians,  boys  and 
men,  and  around  the  camp  fire  that  night  gave  us  a  dramatic  ac- 
count of  his  fomier  trip  down  river.  At  one  point  he  leaped  to 
his  feet,  and  with  an  imaginary  pole  shifted  the  canoe  in  a  swift 
rapid,  turned  it  aside  from  imminent  wreck,  and  shouting  at  the 
top  of  his  voice  over  the  roar  of  the  water  finally  succeeded  in 
evading  what  he  had  made  seem  certain  death  in  a  whirlpool.  We 
kept  a  fire  going  all  night  long  for  we  slept  upon  the  ground  with- 
out a  covering,  and,  strange  as  it  may  appear,  the  cold  seemed  in- 
tense, though  the  minimum  thermometer  registered  59°  F.  The 
next  morning  the  whole  party  of  ten  sunned  themselves  for  nearly 
an  hour  until  the  flies  and  heat  once  more  drove  them  to  shelter. 

Returning  to  camp  next  day  by  a  different  route  was  an  experi- 
ence of  great  interest,  because  of  the  light  it  threw  on  hidden  trails 
known  only  to  the  Indian  and  his  friends.  Slave  raiders  in  former 
years  devastated  the  native  villages  and  forced  the  Indian  to  con- 
ceal his  special  trails  of  refuge.  At  one  point  we  traversed  a 
cliff  seventy-five  feet  above  the  river,  walking  on  a  narrow  ledge 
no  wider  than  a  man's  foot.  At  another  point  the  dim  trail  ap- 
parently disappeared,  but  when  we  had  climbed  hand  over  hand 
up  the  face  of  the  cliff,  by  hanging  vines  and  tree  roots,  we  came 
upon  it  again.  Crossing  the  river  in  the  canoe  we  had  used  the 
day  before,  we  shortened  the  return  by  wading  the  swift  Chi- 
rumbia  waist-deep,  and  by  crawling  along  a  cliff  face  for  nearly  an 
eight li  of  a  mile.  At  the  steepest  point  the  river  had  so  under- 
cut the  face  that  there  was  no  trail  at  all,  and  we  swung  fully  fif- 
teen feet  from  one  ledge  to  another,  on  a  hanging  vine  high  above 
the  river. 

After  two  days'  delay  we  left  Rosalina  late  in  the  afternoon 
of  August  7.    My  party  included  several  Machiganga  Indians,  La 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA        13 

Sama,  and  Dr.  W.  G.  Erving,  surgeon  of  the  expedition.  Mr.  P. 
B.  Lanius,  Moscoso  (the  arriero),  and  two  peons  were  to  take  the 
pack  train  as  far  as  possible  toward  the  rubber  station  at  Pongo 
de  Mainique  where  preparations  were  to  be  made  for  our  arrival. 
At  the  first  rapid  we  learned  the  method  of  our  Indian  boatmen. 
It  was  to  run  the  heavy  boat  head  on  into  shallow  water  at  one 
side  of  a  rapid  and  in  this  way  ' '  brake ' '  it  down  stream.  Heavily 
loaded  with  six  men,  200  pounds  of  baggage,  a  dog,  and  supplies 
of  yuca  and  sugar  cane  our  twenty-five  foot  dugout  canoe  was  as 
rigid  as  a  steamer,  and  we  dropped  safely  dow^n  rapid  after  rapid 
until  long  after  dark,  and  by  the  light  of  a  glorious  tropical  moon 
we  beached  our  craft  in  front  of  La  Sama's  hut  at  the  edge  o.f 
the  cane  swamp. 

Here  for  five  days  we  endured  a  most  exasperating  delay.  La 
Sama  had  promised  Indian  boatmen  and  now  said  none  had  yet 
been  secured.  Each  day  Indians  were  about  to  arrive,  but  by 
nightfall  the  promise  was  broken  only  to  be  repeated  the  follow- 
ing morning.  To  save  our  food  supply — we  had  taken  but  six 
days'  provisions — we  ate  yuca  soup  and  fish  and  some  parched 
corn,  adding  to  this  only  a  little  from  our  limited  stores.  At  last 
we  could  wait  no  longer,  even  if  the  map  had  to  be  sacrificed  to 
the  work  of  navigating  the  canoe.  Our  determination  to  leave 
stirred  La  Sama  to  final  action.  He  secured  an  assistant  named 
Wilson  and  embarked  with  us,  planning  to  get  Indians  farther 
down  river  or  make  the  journey  himself. 

On  August  12,  at  4.30  P.  M.,  we  entered  upon  the  second  stage 
of  the  journey.  As  we  shot  do^\^l  the  first  long  rapid  and  rounded 
a  wooded  bend  the  view  down  river  opened  up  and  gave  us  our 
first  clear  notion  of  the  region  we  had  set  out  to  explore.  From 
mountain  summits  in  the  clouds  long  trailing  spurs  descend  to  the 
river  bank.  In  general  the  slopes  are  smooth-contoured  and  for- 
est-clad from  summit  to  base ;  only  in  a  few  places  do  high  cliffs 
diversify  the  scenery.  The  river  vista  everywhere  includes  a 
rapid  and  small  patches  of  playa  or  flood  plain  on  the  inside  of 
the  river  curves.  Although  a  true  canyon  hems  in  the  river  at 
two  celebrated  passes  farther  down,  the  upper  part  of  the  river 


14  THE  ANDES  OF  SOUTHERN  PERU 

flows  in  a  somewhat  open  valley  of  moderate  relief,  with  here  and 
there  a  sentinel-like  peak  next  the  river. 

A  light  shower  fell  at  sunset,  a  typical  late-afternoon  down- 
pour so  characteristic  of  the  tropics.  AYe  landed  at  a  small  en- 
campment of  Machigangas,  built  a  fire  against  the  scarred  trunk 
of  a  big  palm,  and  made  up  our  beds  in  the  open,  covering  them 
with  our  rubber  ponchos.  Our  Indian  neighbors  gave  us  yuca  and 
corn,  but  their  neighborliness  went  no  further,  for  when  our  boat- 
men attempted  to  sleep  under  their  roofs  they  drove  them  out  and 
fastened  as  securely  as  possible  the  shaky  door  of  their  hut. 

All  our  efforts  to  obtain  Indians,  both  here  and  elsewhere, 
proved  fruitless.  One  excuse  after  another  was  overcome;  they 
plainly  coveted  the  trinkets,  knives,  machetes,  muskets,  and  am- 
munition that  we  offered  them;  and  they  appeared  to  be  friendly 
enough.  Only  after  repeated  assurances  of  our  friendship  could 
we  learn  the  real  reason  for  their  refusal.  Some  of  them  were 
escaped  rubber  pickers  that  had  been  captured  by  white  raiders 
several  years  before,  and  for  them  a  return  to  the  rubber  country 
meant  enslavement,  heavy  floggings,  and  separation  from  their 
numerous  wives.  The  hardships  they  had  endured,  their  final 
escape,  the  cruelty  of  the  rubber  men,  and  the  difficult  passage  of 
the  rapids  below  were  a  set  of  circumstances  that  nothing  in  our 
list  of  gifts  could  overcome.  My  first  request  a  week  before  had  so 
sharpened  their  memory  that  one  of  them  related  the  story  of  his 
wrongs,  a  recital  intensely  dramatic  to  the  whole  circle  of  his 
listeners,  including  myself.  Though  I  did  not  understand  the  de- 
tails of  his  story,  his  tones  and  gesticulations  were  so  effective 
that  they  hold  me  as  well  as  his  kinsmen  of  the  woods  spellbound 
for  over  an  hour. 

It  is  appalling  to  what  extent  this  great  region  has  been  de- 
^populatcd  by  the  slave  raiders  and  those  arch  enemies  of  the 
savage,  Rm.-dlpox  and  malaria.  At  llosalina,  over  sixty  Indians 
died  of  malaria  in  one  year;  and  only  twenty  years  ago  seventy  of 
them,  the  entire  population  of  the  Pongo,  were  swept  away  by 
smallpox.  For  a  week  we  passed  former  camps  near  small  aban- 
doned clearings,  once  the  home  of  little  groups  of  Machigangas. 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA        16 

Even  the  summer  shelter  huts  on  the  sand-bars,  where  the  Indians 
formerly  gathered  from  their  hill  homes  to  fish,  are  now  almost 
entirely  abandoned.  Though  our  men  carefully  reconnoitered  each 
one  for  fear  of  ambush,  the  precaution  was  needless.  Below  the 
Coribeni  the  Urubamba  is  a  great  silent  valley.  It  is  fitted  by 
Nature  to  support  numerous  villages,  but  its  vast  solitudes  are 
unbroken  except  at  night,  when  a  few  families  that  live  in  the  hills 
slip  down  to  the  river  to  gather  yuca  and  cane. 

By  noon  of  the  second  day's  journey  we  reached  the  head  of 
the  great  rapid  at  the  mouth  of  the  Sirialo.  We  had  already  run 
the  long  Coribeni  rapid,  visited  the  Indian  huts  at  the  junction 
of  the  big  Coribeni  tributary,  exchanged  our  canoe  for  a  larger 
and  steadier  one,  and  were  now  to  run  one  of  the  ugliest  rapids  of 
the  upper  river.  The  rapid  is  formed  by  the  gravel  masses  that 
the  Sirialo  brings  down  from  the  distant  Cordillera  Vilcapampa. 
They  trail  along  for  at  least  a  half-mile,  split  the  river  into  two 
main  currents  and  nearly  choke  the  mouth  of  the  tributary.  For 
almost  a  mile  above  this  great  barrier  the  main  river  is  ponded 
and  almost  as  quiet  as  a  lake. 

We  let  our  craft  down  this  rapid  by  ropes,  and  in  the  last  dif- 
ficult passage  were  so  roughly  handled  by  our  almost  unmanagea- 
ble canoe  as  to  suffer  from  several  bad  accidents.  All  of  the  party 
were  injured  in  one  way  or  another,  while  I  suffered  a  fracture 
sprain  of  the  left  foot  that  made  painful  work  of  the  rest  of  the 
river  trip. 

At  two  points  below  Bosalina  the  Urubamba  is  shut  in  by  steep 
mountain  slopes  and  vertical  cliffs.  Canoe  navigation  below  the 
Sirialo  and  Coribeni  rapids  is  no  more  hazardous  than  on  the 
rapids  of  our  northern  rivers,  except  at  the  two  "pongos"  or  nar- 
row passages.  The  first  occurs  at  the  sharpest  point  of  the  abrupt 
curve  shown  on  the  map;  the  second  is  the  celebrated  Pongo  de 
Mainique.  In  these  narrow  passages  in  time  of  high  water  there 
is  no  landing  for  long  stretches.  The  bow  paddler  stands  well 
forward  and  tries  for  depth  and  current;  the  stern  paddler  keeps 
the  canoe  steady  in  its  course.  When  paddlers  are  in  agreement 
even  a  heavy  canoe  can  be  directed  into  the  most  favorable  chan- 


16  THE  ANDES  OF  SOUTHERN  PERU 

nels.  Our  canoemen  were  always  iu  disagreement,  however,  and 
as  often  as  not  we  shot  down  rapids  at  a  speed  of  twenty  miles  an 
hour,  broadside  on,  with  an  occasional  bump  on  projecting  rocks 
or  boulders  whose  warning  ordinary  boatmen  would  not  let  go 
unheeded. 

The  scenery  at  the  great  bend  is  unusually  beautiful.  The 
tropical  forest  crowds  the  river  bank,  great  cliffs  rise  sheer  from 
the  water's  edge,  their  faces  overhung  with  a  trailing  drapery  of 
vines,  and  in  the  longer  river  vistas  one  may  sometimes  see  the 
distant  heights  of  the  Cordillera  Vilcapampa.  We  shot  the  long 
succession  of  rapids  in  the  first  canyon  without  mishap,  and  at 
night  pitched  our  tent  on  the  edge  of  the  river  near  the  mouth  of 
the  Manugali. 

From  the  sharp  peak  opposite  our  camp  we  saw  for  the  first 
time  the  phenomenon  of  cloud-banners.  A  light  breeze  was  blow- 
ing from  the  western  mountains  and  its  vapor  was  condensed  into 
clouds  that  floated  down  the  wind  and  dissolved,  while  they  were 
constantly  forming  afresh  at  the  summit.  In  the  night  a  thunder- 
storm arose  and  swept  with  a  roar  through  the  vast  forest  above 
us.  The  solid  canopy  of  the  tropical  forest  fairly  resounded  with 
the  impact  of  the  heavy  raindrops.  The  next  morning  all  the 
brooks  from  the  farther  side  of  the  river  were  in  flood  and  the 
river  discolored.  When  we  broke  camp  the  last  mist  wraiths  of 
the  storm  were  still  trailing  through  the  tree-tops  and  wrapped 
about  the  peak  opposite  our  camp,  only  parting  now  and  then  to 
give  us  delightful  glimpses  of  a  forest-clad  summit  riding  high 
above  the  clouds. 

The  alternation  of  deeps  and  shallows  at  this  point  in  the  river 
and  the  well-developod  canyon  meanders  are  among  the  most  cele- 
brated of  their  kind  in  Die  world.  Though  shut  in  by  high  cliffs 
and  borderoc]  by  mountains  the  river  exhibits  a  succession  of 
curves  so  regular  tliat  one  might  almost  imagine  the  country  a 
plain  from  the  pattern  of  the  meanders.  The  succession  of  smooth 
curves  for  a  long  distance  across  existing  mountains  points  to  a 
time  when  a  lowland  ])lMin  with  moderate  slopes  drained  by 
strongly  meanclcriiig  rivers  was  developed  here.    Uplift  afforded 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA        17 

a  chance  for  renewed  down-cutting  on  the  part  of  all  the 
streams,  and  the  incision  of  the  meanders.  The  present  meanders 
are,  of  course,  not  the  identical  ones  that  were  formed  on  the  low- 
land plain;  they  are  rather  their  descendants.  Though  they  still 
retain  their  strongly  curved  quality,  and  in  places  have  almost 
cut  through  the  narrow  spurs  between  meander  loops,  they  are  not 
smooth  like  the  meanders  of  the  Mississippi.  Here  and  there  are 
sharp  irregular  turns  that  mar  the  symmetry  of  the  larger  curves. 
The  alternating  bands  of  hard  and  soft  rock  have  had  a  large  part 
in  making  the  course  more  irregular.  The  meanders  have  re- 
sponded to  the  rock  structure.  Though  regular  in  their  broader 
features  they  are  irregular  and  deformed  in  detail. 

Deeps  and  shallows  are  known  in  every  vigorous  river,  but  it  is 
seldom  that  they  are  so  prominently  developed  as  in  these  great 
canyons.  At  one  point  in  the  upper  canyon  the  river  has  been 
broadened  into  a  lake  two  or  three  times  the  average  width  of  the 
channel  and  with  a  scarcely  perceptible  current ;  above  and  below 
the  "laguna,"  as  the  boatmen  call  it,  are  big  rapids  with  beds  so 
shallow  that  rocks  project  in  many  places.  In  the  Pongo  de 
Mainique  the  river  is  at  one  place  only  jBfty  feet  wide,  yet  so  deep 
that  there  is  little  current.  It  is  on  the  banks  of  the  quiet 
stretches  that  the  red  forest  deer  grazes  under  leafy  arcades. 
Here,  too,  are  the  boa-constrictor  trails  several  feet  wide  and  bare 
like  a  roadway.  At  night  the  great  serpents  come  trailing  down 
to  the  river's  edge,  where  the  red  deer  and  the  wildcat,  or  so- 
called  "tiger,"  are  their  easy  prey. 

It  is  in  such  quiet  stretches  that  one  also  finds  the  vast  colonies 
of  water  skippers.  They  dance  continuously  in  the  sun  mth  an  in- 
cessant motion  from  right  to  left  and  back  again.  Occasionally 
one  dances  about  in  circles,  then  suddenly  darts  through  the  entire 
mass,  though  without  striking  his  equally  erratic  neighbors.  An 
up-and-down  motion  still  further  complicates  the  effect.  It  is  posi- 
tively bewildering  to  look  intently  at  the  whirling  multitude  and 
try  to  follow  their  complicated  motions.  Every  slight  breath  of 
wind  brings  a  shock  to  the  organization  of  the  dance.  For  though 
they  dance  only  in  the  sun,  their  favorite  places  are  the  sunny 


\ 


18  THE  ANDES  OF  SOUTHERN  PERU 

spots  in  the  shade  near  the  bank,  as  beneath  an  overhanging  tree. 
When  the  wind  shakes  the  foliage  the  mottled  pattern  of  shade  and 
sunlight  is  confused,  the  dance  slows  doAvn,  and  the  dancers  be- 
come bewildered.  In  a  storm  they  seek  shelter  in  the  jungle.  The 
hot,  quiet,  sunlit  days  bring  out  literally  millions  of  these  tiny 
creatures. 

One  of  the  longest  deeps  in  the  whole  Urubamba  lies  just  above 
the  Pongo  at  Mulanquiato.  We  drifted  down  with  a  gentle  cur- 
rent just  after  sunset.  Shrill  whistles,  like  those  of  a  steam 
launch,  sounded  from  either  bank,  the  strange  piercing  notes  of 
the  lowland  cicada,  cicada  tibicen.  Long  decorated  canoes,  bet- 
ter than  any  we  had  yet  seen,  were  dra^vn  up  in  the  quiet  coves. 
Soon  we  came  upon  the  first  settlement.  The  owner,  Senor 
Pereira,  has  gathered  about  him  a  group  of  Machigangas,  and  by 
marrying  into  the  tribe  has  attained  a  position  of  great  influence 
among  the  Indians.  Upon  our  arrival  a  gun  was  fired  to  announce 
to  his  people  that  strangers  had  come,  upon  which  the  Machi- 
gangas strolled  along  in  twos  and  threes  from  their  huts,  helped 
us  ashore  with  the  baggage,  and  prepared  the  evening  meal.  Here 
we  sat  dovra  with  five  Italians,  who  had  ventured  into  the  rubber 
fields  with  golden  ideas  as  to  profits.  After  having  lost  the  larger 
part  of  their  merchandise,  chiefly  cinchona,  in  the  rapids  the  year 
before,  they  had  established  themselves  here  with  the  idea  of  pick- 
ing rubber.  Without  capital,  they  followed  the  ways  of  the  itiner- 
ant rubber  picker  and  had  gathered  "caucho,"  the  poorer  of  the 
two  kinds  of  rubber.  No  capital  is  required;  the  picker  simply 
cuts  down  the  likeliest  trees,  gathers  the  coagulated  sap,  and  floats 
it  down-stream  to  market.  After  a  year  of  this  life  they  had 
grouTi  restless  and  were  venturing  on  other  schemes  for  the  great 
down-river  rubber  country. 

A  few  weeks  later,  on  returning  through  the  forest,  we  met 
their  carriers  with  a  few  small  bundles,  the  only  part  of  their 
cargo  they  had  saved  from  tlie  river.  Without  a  canoe  or  the 
means  to  buy  one  they  had  built  rafts,  which  were  quickly  torn  to 
pieces  in  the  rapids.  We,  too,  should  have  said  "pohres  Italianos" 
if  their  venture  had  not  been  plainly  foolish.     The  rubber  terri- 


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Fio.    10. 


J.  l(i  15 — Topogriijiliy  iiml  v<'^((l;i(  iuii  fruiii  (lie  'I'ocatr  puHH,  7,HI()  feet  (2,1(14  in.), 
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the  enrly  nft^Tnoon. 

fir,,  ir — Tin-  Kxpr(Iiti(in"H  thirty-foot  ciinoc  «(  tlic  rin.iitli  of  the  Tinij)iii  below 
Pongo  (]>•   .Mainifnic. 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA        19 

tory  is  difficult  enough  for  men  with  capital;  for  men  with- 
out capital  it  is  impossible.  Such  men  either  become  affiliated 
with  organized  companies  or  get  out  of  the  region  when  they 
can.  A  few,  made  desperate  by  risks  and  losses,  cheat  and  steal 
their  way  to  rubber.  Two  years  before  our  trip  an  Italian  had 
murdered  two  Frenchmen  just  below  the  Pongo  and  stolen  their 
rubber  cargo,  whereupon  he  was  shot  by  Machigangas  under  the 
leadership  of  Domingo,  the  chief  who  was  with  us  on  a  journey 
from  Pongo  de  Mainique  to  the  mouth  of  the  Timpia.  After- 
ward they  brought  his  skull  to  the  top  of  a  pass  along  the  forest 
trail  and  set  it  up  on  a  cliff  at  the  very  edge  of  Machiganga-land 
as  a  warning  to  others  of  his  kind. 

At  Mulanquiato  we  secured  five  Machigangas  and  a  boy  inter- 
preter, and  on  August  17  made  the  last  and  most  difficult  portion 
of  our  journey.  We  found  these  Indians  much  more  skilful  than 
our  earlier  boatmen.  Well-trained,  alert,  powerful,  and  with  ex- 
cellent team-play,  they  swept  the  canoe  into  this  or  that  thread 
of  the  current,  and  took  one  after  another  of  the  rapids  with  the 
greatest  confidence.  No  sooner  had  we  passed  the  Sintulini  rapids, 
fully  a  mile  long,  than  we  reached  the  mouth  of  the  Pomareni. 
This  swift  tributary  comes  in  almost  at  right  angles  to  the  main 
river  and  gives  rise  to  a  confusing  mass  of  standing  waves  and 
conflicting  currents  rendered  still  more  difficult  by  the  whirlpool 
just  below  the  junction.  So  swift  is  the  circling  current  of  the 
maelstrom  that  the  water  is  hollowed  out  like  a  great  bowl,  a  really 
formidable  point  and  one  of  our  most  dangerous  passages ;  a  little 
too  far  to  the  right  and  we  should  be  thrown  over  against  the  cliff- 
face;  a  little  too  far  to  the  left  and  we  should  be  caught  in  the 
whirlpool.  Once  in  the  swift  current  the  canoe  became  as  help- 
less as  a  chip.  It  was  turned  this  way  and  that,  each  turn  head- 
ing it  apparently  straight  for  destruction.  But  the  Indians  had 
judged  their  position  well,  and  though  we  seemed  each  moment  in 
a  worse  predicament,  we  at  last  skimmed  the  edge  of  the  whirl- 
pool and  brought  our  canoe  to  shore  just  beyond  its  rim. 

A  little  farther  on  we  came  to  the  narrow  gateway  of  the 
Pongo,  where  the  entire  volume  of  the  river  flows  between  cliffs 


20  THE  ANDES  OF  SOUTHERN  PERU 

at  one  point  no  more  than  fifty  feet  apart.  Here  are  concentrated 
the  worst  rapids  of  the  lower  Urubamba.  For  nearly  fifteen 
miles  the  river  is  an  unbroken  succession  of  rapids,  and  once 
within  its  walls  the  Pongo  offers  small  chance  of  escape.  At  some 
points  we  were  fortunate  enough  to  secure  a  foothold  along  the 
edge  of  the  river  and  to  let  our  canoe  down  by  ropes.  At  others 
we  were  obliged  to  take  chances  with  the  current,  though  the  great 
depth  of  water  in  most  of  the  Pongo  rapids  makes  them  really  less 
formidable  in  some  respects  than  the  shallow  rapids  up  stream. 
The  chief  danger  here  lies  in  the  rotary  motion  of  the  water  at  the 
sharpest  bends.  The  effect  at  some  places  is  extraordinary.  A 
floating  object  is  carried  across  stream  like  a  feather  and  driven 
at  express-train  speed  against  a  solid  cliff.  In  trying  to  avoid  one 
of  these  cross-currents  our  canoe  became  turned  midstream,  we 
were  thrown  this  way  and  that,  and  at  last  shot  through  three 
standing  waves  that  half  filled  the  canoe. 

Below  the  worst  rapids  the  Pongo  exhibits  a  swift  succession 
of  natural  wonders.  Fern-clad  cliffs  border  it,  a  bush  resembling 
the  juniper  reaches  its  dainty  finger-like  stems  far  out  over  the 
river,  and  the  banks  are  heavily  clad  with  mosses.  The  great 
woods,  silent,  impenetrable,  mantle  the  high  slopes  and  stretch  up 
to  the  limits  of  vision.  Cascades  tumble  from  the  cliff  summits 
or  go  rippling  down  the  long  inclines  of  the  slate  beds  set  almost 
on  edge.  Finally  appear  the  white  pinnacles  of  limestone  that  hem 
in  the  narrow  lower  entrance  or  outlet  of  the  Pongo.  Beyond  this 
passage  one  suddenly  comes  out  upon  the  edge  of  a  rolling  forest- 
clad  region,  llio  rubber  territory,  the  country  of  the  great  woods. 
Here  the  Andean  realm  ends  and  Amazonia  begins. 

J^'rom  the  summits  of  the  white  cliffs  4,000  feet  above  the  river 
we  were  in  a  few  days  to  have  one  of  the  most  extensive  views  in 
Sonfli  America.  Tlio.broak  between  the  Andean  Cordillera  and  the 
ii ill-dotted  plains  of  the  lower  Urubamba  valley  is  almost  as  sharp 
MH  a  shoreline.  The  rolling  plains  are  covered  with  leagues  upon 
leagues  of  dense,  shadowy,  fever-haunted  jungle.  The  great  river 
winds  through  in  a  series  of  splendid  mennders,  and  with  so  broad 
a  channel  as  to  make  it  visible  almost  to  the  horizon.    Down  river 


THE  RAPIDS  AND  CANYONS  OF  THE  URUBAMBA        21 

from  our  lookout  one  can  reach  ocean  steamers  at  Iquitos  with 
less  than  two  weeks  of  travel.  It  is  three  weeks  to  the  Pacific 
via  Cuzco  and  more  than  a  month  if  one  takes  the  route  across 
the  high  bleak  lava-covered  country  which  we  were  soon  to  cross 
on  our  way  to  the  coast  at  Camana. 


CHAPTER  III 
THE  RUBBER  FORESTS 

The  white  limestone  cliffs  at  Pongo  de  Mainique  are  a  bound- 
ary between  two  great  geographic  provinces  (Fig.  17).  Do\\ti  val- 
ley are  the  vast  river  plains,  drained  by  broad  meandering  rivers ; 


Fjg.  17 — Regional  diagram  of  the  Eastern  Andes  (here  the  Cordillera  Vilcapampa) 
and  the  adjacent  tropical  plains.  For  an  explanation  of  the  method  of  construction 
and  the  symhoHHm  of  the  diagram  sec  p.  51. 

up  valley  are  the  rugged  spurs  of  the  eastern  Andes  and  their  en- 
canyoned  streams  (Kig.  18).  There  are  outliers  of  the  Andes  still 
farther  toward  the  iiortlieast  where  hangs  the  inevitable  haze  of 
the  tropical  horizon,  but  the  country  beyond  them  differs  in  no 
important  respect  from  lliat   immediately  below  the  Pongo. 

The  foot-path  to  the  summit  of  llic  cliffs  is  too  narrow  and 

22 


THE  RUBBER  FORESTS 


23 


steep  for  even  the  most 
agile  mules.  It  is  simply 
impassable  for  animals 
without  hands.  In  places 
the  packs  are  lowered  by 
ropes  over  steep  ledges 
and  men  must  scramble 
down  from  one  project- 
ing root  or  swinging  vine 
to  another.  In  the  breath- 
less jungle  it  is  a  wearing 
task  to  pack  in  all  sup- 
plies for  the  station  be- 
low the  Pongo  and  to 
carry  out  the  season's 
rubber.  Recently  however 
the  ancient  track  has  been 
replaced  by  a  road  that 
was  cut  with  great  la- 
bor, and  by  much  blast- 
ing, across  the  mountain 
barrier,  and  at  last  mule 
transport  has  taken  the 
place  of  the  Indian. 

In  the  dry  season  it 
is  a  fair  and  delightful 
country — that  on  the  bor- 
der of  the  mountains.  In 
the  wet  season  the  trav- 
eler is  either  actually  ma- 
rooned or  he  must  slosh 
through  rivers  of  mud 
and  water  that  deluge  the 
trails  and  break  the 
hearts  of  his  beasts  (Fig. 
14).     Here   and   there    a 


Fig.  18 — Index  map  for  the  nine  regional 
diagrams  in  the  pages  following,  A  rep- 
resents Fig.  17;  B,  42;  C,  36;  D,  32;  E,  34; 
F,  25;   G,  26;   and  H,  65. 


24)  THE  ANDES  OF  SOUTHERN  PERU 

large  shallow-rooted  tree  has  come  crashing  down  across  the 
trail  and  with  its  four  feet  of  circumference  and  ten  feet  of 
plank  buttress  it  is  as  difficult  to  move  as  a  house.  A  new  trail 
must  be  cut  around  it.  A  little  farther  on,  where  the  valley- 
wall  steepens  and  one  may  look  down  a  thousand  feet  of  slope 
to  the  bed  of  a  mountain  torrent,  a  patch  of  trail  has  become 
soaked  with  water  and  the  mules  pick  their  way,  trembling, 
across  it.  Two  days  from  Yavero  one  of  our  mules  went 
over  the  trail,  and  though  she  was  finally  recovered  she  died  of 
her  injuries  the  following  night.  After  a  month's  work  in  the 
forest  a  mule  must  run  free  for  two  months  to  recover.  The  pack- 
ers count  on  losing  one  beast  out  of  five  for  every  journey  into  the 
forest.  It  is  not  solely  a  matter  of  work,  though  this  is  terrific; 
it  is  quite  largely  a  matter  of  forage.  In  spite  of  its  profusion 
of  life  (Fig.  13)  and  its  really  vast  wealth  of  species,  the  tropical 
forest  is  all  but  barren  of  grass.  Sugar  cane  is  a  fair  substitute, 
but  there  are  only  a  few  cultivated  spots.  The  more  tender  leaves 
of  the  trees,  the  young  shoots  of  cane  in  the  carrizo  swamps, 
and  the  grass-like  foliage  of  the  low  bamboo  are  the  chief  substi- 
tutes for  pasture.  But  they  lead  to  various  disorders,  besides  re- 
quiring considerable  labor  on  the  part  of  the  dejected  peons  who 
must  gather  them  after  a  day's  heavy  work  with  the  packs. 

Overcoming  these  enormous  difficulties  is  expensive  and  some 
one  must  pay  tlie  Ijill.  As  is  usual  in  a  pioneer  region,  the  native 
laborer  pays  a  large  part  of  it  in  unrequited  toil ;  the  rest  is  paid 
by  the  rubber  consumer.  For  this  is  one  of  the  cases  where  a 
direct  road  connects  the  civilized  consumer  and  the  barbarous  pro- 
ducer. What  a  story  it  could  tell  if  a  ball  of  smoke-cured  rubber 
on  a  New  York  dock  were  endowed  with  speech — of  the  wet  jungle 
path,  of  enslaved  peons,  of  vile  abuses  by  immoral  agents,  of  all 
the  toil  and  sickness  that  make  tlio  tropical  lowland  a  reproach ! 

Ill  tlio  I'liitf'd  States  the  specter  of  slavery  haunted  the  na- 
tional ('f)iiHci<'nc»'  almost  from  the  beginning  of  national  life,  and 
tlie  ghost  was  laid  only  at  the  cost  of  one  of  the  bloodiest  wars  in 
history.  Tn  other  countries,  as  in  sugar-producing  Brazil,  the 
freeing  of  the  slaves  meant  not  a  war  but  the  verge  of  financial 


Fig.   19. 


Fig.  19 — Moss-draped  trees  in  the  rain  forest  near  Abra  Tocate  between  Rosalina 
and   Pongo  de   Jlainique. 

Fig.  20 — Yavero,  a  rubber  station  on  tlie  Yavero  (Paucartambo)  River,  a  tributary 
of  tlie  Urubamba.     Elevation   1,000  feet    (490  m.). 


Kio.  21  — (  Ifiiriiit;  ill  lln'  lrn|)i(;il  finTHt  liclwccti  II()s;irm:i  mid  r;ilicll()ii.  This 
rcprcHt'Titn  the  horih-r  rvniitu  where  the  foreHl-dwellin^  Miichi^iinjia  liidiiUiH  ami  liie 
moiinliiiii  lniliiiii!4  meet.  Tlie  (leniin^'H  iire  ii((H|)ic(l  hy  .M;i(liij,'an^!is  whose  oliief  cropH 
arr  yiien  ami  ('(trn ;  in  Die  extreme  u|i|ier  hft  hand  corner  are  grassy  shjpes  occupied 
by   f^nechiia    lierdHnien    niid    fnriiiei'H   who   ;;in\v    potatoes   and   corn. 


THE  RUBBER  FORESTS  25 

ruin  besides  a  fundamental  change  in  the  social  order  and  prob- 
lems as  complex  and  wearisome  as  any  that  war  can  bring. 
Everywhere  abolition  was  secured  at  frightful  cost. 

The  spirit  that  upheld  the  new  founders  of  the  western  repub- 
lics in  driving  out  slavery  was  admirable,  but  as  much  cannot  be 
said  of  their  work  of  reconstruction.  We  like  to  pass  over  those 
dark  days  in  our  own  history.  In  South  America  there  has  lin- 
gered from  the  old  slave-holding  days  down  to  the  present,  a  labor 
system  more  insidious  than  slavery,  yet  no  less  revolting  in  its  de- 
tails, and  infinitely  more  difficult  to  stamp  out.  It  is  called 
peonage ;  it  should  be  called  slavery.  In  Bolivia,  Peru,  and  Brazil 
it  flourishes  now  as  it  ever  did  in  the  fruitful  soil  of  the  interior 
provinces  where  law  and  order  are  bywords  and  where  the  scarcity 
of  workmen  will  long  impel  men  to  enslave  labor  when  they  can- 
not employ  it.  Peonage  is  slavery,  though  as  in  all  slave  systems 
there  are  many  forms  under  which  the  system  is  worked  out.  We 
commonly  think  that  the  typical  slave  is  one  who  is  made  to  work 
hard,  given  but  little  food,  and  at  the  slightest  provocation  is  tied 
to  a  post  and  brutally  whipped.  This  is  indeed  the  fate  of  many 
slaves  or  "peons"  so-called,  in  the  Amazon  forests;  but  it  is  no 
more  the  rule  than  it  was  in  the  South  before  the  war,  for  a  peon 
is  a  valuable  piece  of  property  and  if  a  slave  raider  travel  five 
hundred  miles  through  forest  and  jungle-swamp  to  capture  an 
Indian  you  may  depend  upon  it  that  he  will  not  beat  him  to  death 
merely  for  the  fun  of  it. 

That  unjust  and  frightfully  cruel  floggings  are  inflicted  at 
times  and  in  some  places  is  of  course  a  result  of  the  lack  of  official 
resti-aint  that  drunken  owners  far  from  the  arm  of  the  law  some- 
times enjoy.  When  a  man  obtains  a  rubber  concession  from  the 
government  he  buys  a  kingdom.  Many  of  the  rubber  territories 
are  so  remote  from  the  cities  that  officials  can  with  great  difficulty 
be  secured  to  stay  at  the  customs  ports.  High  salaries  must  be 
paid,  heavy  taxes  collected,  and  grafting  of  the  most  flagrant  kind 
winked  at.  Often  the  concessionaire  himself  is  chief  magistrate 
of  his  kingdom  by  law.  Under  such  a  system,  remote  from  all 
civilizing  influences,  the  rubber  producer  himself  oftentimes  a  law- 


26  THE  ANDES  OF  SOUTHERN  PERU 

less  border  character  or  a  downright  criminal,  no  system  of  gov- 
ernment would  be  adequate,  least  of  all  one  like  peonage  that  per- 
mits or  ignores  flagrant  wrongs  because  it  is  so  expensive  to  en- 
force justice. 

The  peonage  system  continues  by  reason  of  that  extraordinary 
difficulty  in  the  development  of  the  tropical  lowland  of  South 
America — the  lack  of  a  labor  supply.  The  population  of  Amazonia 
now  numbers  less  than  one  person  to  the  square  mile.  The  people 
are  distributed  in  small  groups  of  a  dozen  to  twenty  each  in  scat- 
tered villages  along  the  river  banks  or  in  concealed  clearings 
reached  by  trails  known  only  to  the  Indians.  Nearly  all  of  them 
still  live  in  the  same  primitive  state  in  which  they  lived  at  the 
time  of  the  Discovery.  In  the  Urubamba  region  a  single  cotton 
shirt  is  worn  by  the  married  men  and  women,  while  the  girls 
and  boys  in  many  cases  go  entirely  naked  except  for  a  loincloth 
or  a  necklace  of  nuts  or  monkeys'  teeth  (Fig.  23).  A  cane  hut 
with  a  thatch  to  keep  out  the  heavy  rains  is  their  shelter  and  their 
food  is  the  yuca,  sugar  cane,  Indian  corn,  bananas  of  many  kinds, 
and  fish.  A  patch  of  yuca  once  planted  will  need  but  the  most 
trifling  attention  for  years.  The  small  spider  monkey  is  their 
greatest  delicacy  and  to  procure  it  they  will  often  abandon  every 
other  project  and  return  at  their  o^vn  sweet  and  belated  will. 

In  the  midst  of  this  natural  life  of  the  forest-dwelling  Indian 
appears  the  rubber  man,  who,  to  gather  rubber,  must  have  rubber 
"pickers."  If  he  lives  on  the  edge  of  the  great  Andean  Cordil- 
lera, laborers  may  be  secured  from  some  of  the  lower  valleys,  but 
they  must  be  paid  well  for  even  a  temporary  stay  in  the  hot  and 
uiiliealthful  lowlands.  Farther  out  in  the  great  forest  country  the 
platf'au  Indians  will  not  go  and  only  the  scattered  tribes  remain 
from  which  to  recruit  laborers.  For  the  nature-life  of  the  Indian 
what  has  the  rub])cr  gatherer  to  offer?  Money?  The  Indian  uses 
it  for  ornament  only.  "When  T  once  tried  with  money  to  pay  an 
Indian  for  a  week's  services  ho  refused  it.  In  exchange  for  his 
severe  labor  he  wanted  nothing  more  than  a  fish-hook  and  a  ring, 
the  two  costing  not  more  tlian  a  penny  apiece!  Wlien  his  love  for 
ornament  has  once  boon  gratified  flio  Indian  ceases  to  work.    His 


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THE  RUBBER  FORESTS  27 

food  and  shelter  and  clothing  are  of  the  most  primitive  kind,  but 
they  are  the  best  in  the  world  for  him  because  they  are  the  only 
kind  he  has  known.  So  where  money  and  finery  fail  the  lash  comes 
in.  The  rubber  man  says  that  the  Indian  is  lazy  and  must  be 
made  to  work;  that  there  is  a  great  deal  of  work  to  be  done  and 
the  Indian  is  the  only  laborer  who  can  be  found;  that  if  rubber 
and  chocolate  are  produced  the  Indian  must  be  made  to  produce 
them;  and  that  if  he  will  not  produce  them  for  pay  he  must  be 
enslaved. 

It  is  a  law  of  the  rubber  country  that  when  an  Indian  falls  into 
debt  to  a  white  man  he  must  work  for  the  latter  until  the  debt  is 
discharged.  If  he  runs  away  before  the  debt  is  canceled  or  if  he 
refuses  to  work  or  does  too  little  work  he  may  be  flogged.  Under 
special  conditions  such  laws  are  wise.  In  the  hands  of  the  rubber 
men  they  are  the  basis  of  slavery.  For,  once  the  rubber  interests 
begin  to  suffer,  the  promoters  look  around  for  a  chance  to  capture 
free  Indians.  An  expedition  is  fitted  out  that  spends  weeks  ex- 
ploring this  river  or  that  in  getting  on  the  track  of  unattached  In- 
dians. When  a  settlement  is  found  the  men  are  enslaved  and  taken 
long  distances  from  home  finally  to  reach  a  rubber  property. 
There  they  are  given  a  corner  of  a  hut  to  sleep  in,  a  few  cheap 
clothes,  a  rubber-picking  outfit,  and  a  name.  In  return  for  these 
articles  the  unwilling  Indian  is  charged  any  fanciful  price  that 
comes  into  the  mind  of  his  '  *  owner, ' '  and  he  must  thereupon  work 
at  a  per  diem  wage  also  fixed  by  the  owner.  Since  his  obligations 
increase  with  time,  the  Indian  may  die  over  two  thousand  dollars 
in  debt ! 

Peonage  has  left  frightful  scars  upon  the  country.  In  some 
places  the  Indians  are  fugitives,  cultivating  little  farms  in  se- 
creted places  but  visiting  them  only  at  night  or  after  carefully  re- 
connoitering  the  spot.  They  change  their  camps  frequently  and 
make  their  way  from  place  to  place  by  secret  trails,  now  spending 
a  night  or  two  under  the  shelter  of  a  few  palm  leaves  on  a  sand- 
bar, again  concealing  themselves  in  almost  impenetrable  jungle. 
If  the  hunter  sometimes  discovers  a  beaten  track  he  follows  it  only 
to  find  it  ending  on  a  cliff  face  or  on  the  edge  of  a  lagoon  where 


28  THE  ANDES  OF  SOUTHERN  PERU 

concealment  is  perfect.  There  are  tribes  that  shoot  the  white  man 
at  sight  and  regard  him  as  their  bitterest  enemy.  Experience  has 
led  them  to  believe  that  only  a  dead  white  is  a  good  white,  revers- 
ing our  saying  about  the  North  American  Indian;  and  that  even 
when  he  comes  among  them  on  peaceful  errands  he  is  likely  to 
leave  behind  him  a  trail  of  sj^hilis  and  other  venereal  diseases 
scarcely  less  deadly  than  his  bullets. 

However,  the  peonage  system  is  not  hideous  everywhere  and  in 
all  its  aspects.  There  are  white  o^vners  who  realize  that  in  the 
long  run  the  friendship  of  the  Indians  is  an  asset  far  greater  than 
unwilling  service  and  deadly  hatred.  Some  of  them  have  indeed 
intermarried  with  the  Indians  and  live  among  them  in  a  state  but 
little  above  savagery.  In  the  Mamore  country  are  a  few  owners 
of  original  princely  concessions  who  have  grown  enormously 
wealthy  and  yet  who  continue  to  live  a  primitive  life  among  their 
scores  of  illegitimate  descendants.  The  Indians  look  upon  them 
as  benefactors,  as  indeed  many  of  them  are,  defending  the  Indians 
from  ill  treatment  by  other  whites,  giving  them  clothing  and  orna- 
ments, and  exacting  from  them  only  a  moderate  amount  of  labor. 
In  some  cases  indeed  the  whites  have  gained  more  than  simple 
gratitude  for  their  humane  treatment  of  the  Indians,  some  of 
whom  serve  their  masters  with  real  devotion. 

AVhen  the  ''rubber  barons"  wish  to  discourage  investigation 
of  their  system  they  invite  the  traveler  to  leave  and  he  is  given 
a  canoe  and  oarsmen  with  which  to  make  his  way  out  of  the  dis- 
trict. Refusal  to  accept  an  offer  of  canoes  and  men  is  a  declara- 
tion of  war.  An  agent  of  one  of  the  London  companies  accepted 
such  a  challenge  and  was  promptly  told  that  he  would  not  leave 
the  territory  alive.  The  threat  would  have  held  true  in  the  case 
of  a  less  skilful  man.  Though  Indians  slept  in  the  canoes  to  pre- 
vent their  seizure,  he  slipped  past  the  guards  in  the  night,  swam 
to  tlif  opposite  shore,  and  tliore  secured  a  canoe  within  which  he 
made  a  dilTicnlt  .iourney  down  river  to  the  nearest  post  where  food 
and  an  outfit  could  be  secured. 

A,  few  companies  operating  on  or  near  the  border  of  the  Cordil- 
lera have  adopted  a  normal  labor  system,  dependent  chiefly  upop 


THE  RUBBER  FORESTS  29 

people  from  the  plateau  and  upon  the  thoroughly  willing  assist- 1 
ance  of  well-paid  forest  Indians.  The  Compania  Gomera  de 
Mainique  at  Puerto  Mainique  just  below  the  Pongo  is  one  of  these  I 
and  its  development  of  the  region  without  \dolation  of  native 
rights  is  in  the  highest  degree  praiseworthy.  In  fact  the  whole 
conduct  of  this  company  is  interesting  to  a  geographer,  as  it 
reflects  at  every  point  the  physical  nature  of  the  country. 

The  government  is  eager  to  secure  foreign  capital,  but  in  east- 
ern Peru  can  offer  practically  nothing  more  than  virgin  wealth, 
that  is,  land  and  the  natural  resources  of  the  land.  There  are  no 
roads,  virtually  no  trails,  no  telegraph  lines,  and  in  most  cases  no 
labor.  Since  the  old  Spanish  grants  ran  at  right  angles  to  the 
river  so  as  to  give  the  owners  a  cross-section  of  varied  resources, 
the  up-river  plantations  do  not  extend  do^Mi  into  the  rubber  coun- 
try. Hence  the  more  heavily  forested  lower  valleys  and  plains 
are  the  property  of  the  state.  A  man  can  buy  a  piece  of  land 
down  there,  but  from  any  tract  mthin  ordinary  means  only  a 
primitive  living  can  be  obtained.  The  pioneers  therefore  are  the 
rubber  men  who  produce  a  precious  substance  that  can  stand  the 
enormous  tax  on  production  and  transportation.  They  do  not 
want  the  land — only  the  exclusive  right  to  tap  the  rubber  trees 
upon  it.  Thus  there  has  arisen  the  concession  plan  whereby  a 
large  tract  is  obtained  under  conditions  of  money  payment  or  of 
improvements  that  will  attract  settlers  or  of  a  tax  on  the  export. 

The  "caucho"  or  poorer  rubber  of  the  Urubamba  Valley  be- 
gins at  3,000  feet  (915  m.)  and  the  "hevea"  or  better  class  is  a 
lower-valley  and  plains  product.  The  rubber  trees  thereabouts 
produce  60  grams  (2  ozs.)  of  dry  rubber  each  week  for  eight 
months.  After  yielding  rubber  for  this  length  of  time  a  tree  is 
allowed  to  rest  four  or  five  years.  *'Caucho"  is  produced  from 
trees  that  are  cut  do"svn  and  ringed  with  machetes,  but  it  is  from 
fifty  to  sixty  cents  cheaper  owing  to  the  impurities  that  get  into 
it.  The  wood,  not  the  nut,  of  the  Palma  carmona  is  used  for  smok- 
ing or  "curing"  the  rubber.  The  government  had  long  been 
urged  to  build  a  road  into  the  region  in  place  of  the  miserable 
track — absolutely  impassable  in  the  wet  season — that  heretofore 


30  THE  ANDES  OF  SOUTHERN  PERU 

constituted  the  sole  means  of  exit.  About  ten  years  ago  Seiior 
Kobledo  at  last  built  a  government  trail  from  Kosalina  to  Yavero 
about  100  miles  long.  While  it  is  a  wretched  trail  it  is  better  than 
the  old  one,  for  it  is  more  direct  and  it  is  better  drained.  In  the 
wet  season  parts  of  it  are  turned  into  rivers  and  lakes,  but  it  is 
probably  the  best  that  could  be  done  with  the  small  grant  of  twenty 
thousand  dollars. 

With  at  least  an  improvement  in  the  trail  it  became  possible 
for  a  rubber  company  to  induce  cargadores  or  packers  to  trans- 
port merchandise  and  rubber  and  to  have  a  fair  chance  of  success. 
Whereupon  a  rubber  company  was  organized  which  obtained  a  con- 
cession of  28,000  hectares  (69,188  acres)  of  land  on  condition  that 
the  company  finish  a  road  one  and  one-half  meters  wide  to  the 
Pongo,  connecting  with  the  road  which  the  government  had  ex- 
tended to  Yavero.  The  land  given  in  payment  was  not  continuous 
but  was  selected  in  lots  by  the  company  in  such  a  way  as  to  secure 
the  best  rubber  trees  over  an  area  several  times  the  size  of  the 
concession.  The  road  was  finished  by  William  Tell  after  four 
years '  work  at  a  cost  of  about  seventy-five  thousand  dollars.  The 
last  part  of  it  was  blasted  out  of  slate  and  limestone  and  in  1912 
the  first  pack  train  entered  Puerto  Mainique. 

The  first  rubber  was  taken  out  in  November,  1910,  and  produc- 
tive possibilities  proved  by  the  collection  of  9,000  kilos  (19,841 
pounds)  in  eight  months. 

If  a  main  road  were  the  chief  problem  of  the  rubber  company 
the  business  would  soon  be  on  a  paying  basis,  but  for  every  mile 
of  road  tliere  must  be  cut  several  miles  of  narrow  trail  (Fig.  14), 
as  the  ru])bor  trees  grow  scattered  about — a  clump  of  a  half  dozen 
here  and  five  hundred  feet  farther  on  another  clump  and  only  scat- 
tered individuals  between.  Furthermore,  about  twenty-five  years 
ago  rubber  men  from  llic  Ucayali  camo  np  bore  in  launches  and 
canoes  and  vn\  down  large  nunil)ors  of  trees  within  reach  of  the 
water  ooursfs  and  l)y  ringing  the  trunks  every  few  feet  with 
machetes  "blfd"  thorn  rapidly  and  thus  covered  a  large  territory 
in  a  short  time,  and  made  hngo  sums  of  money  when  the  price  of 
rubber  was  high.     Only  a  few  of  the  small  trees  that  were  left 


THE  RUBBER  FORESTS  31 

are  now  mature.  These,  the  mature  trees  that  were  overlooked, 
and  the  virgin  stands  farther  from  the  rivers  are  the  present 
sources  of  rubber. 

In  addition  to  the  trails  small  cabins  must  be  built  to  shelter 
the  hired  laborers  from  the  plateau,  many  of  whom  bring  along 
their  women  folk  to  cook  for  them.  The  combined  expense  to  a 
company  of  these  necessary  improvements  before  production  can 
begin  is  exceedingly  heavy.  There  is  only  one  alternative  for  the 
prospective  exploiter :  to  become  a  vagrant  rubber  gatherer.  With 
tents,  guns,  machetes,  cloth,  baubles  for  trading,  tinned  food  for 
emergencies,  and  with  pockets  full  of  English  gold  parties  have 
started  out  to  seek  fortunes  in  the  rubber  forests.  If  the  friend- 
ship of  a  party  of  Indians  can  be  secured  by  adequate  gifts  large 
amounts  of  rubber  can  be  gathered  in  a  short  time,  for  the  Indians 
know  where  the  rubber  trees  grow.  On  the  other  hand,  many  for- 
tunes have  been  lost  in  the  rubber  country.  Some  of  the  tribes 
have  been  badly  treated  by  other  adventurers  and  attack  the  new- 
comers from  ambush  or  gather  rubber  for  a  while  only  to  over- 
turn the  canoe  in  a  rapid  and  let  the  river  relieve  them  of  selfish 
friends. 

The  Compania  Gomera  de  Mainique  started  out  by  securing  the 
good-will  of  the  forest  Indians,  the  Machigangas.  They  come 
and  go  in  friendly  visits  to  the  port  at  Yavero.  If  one  of  them  is 
sick  he  can  secure  free  medicine  from  the  agent.  If  he  wishes 
goods  on  credit  he  has  only  to  ask  for  them,  for  the  agent  knows 
that  the  Indian's  sense  of  fairness  will  bring  him  back  to  work 
for  the  company.  Without  previous  notice  a  group  of  Indians 
appears : 

"We  owe,"  they  announce. 

"Good,"  says  the  agent,  "build  me  a  house." 

They  select  the  trees.  Before  they  cut  them  down  they  address 
them  solemnly.  The  trees  must  not  hold  their  destruction  against 
the  Indians  and  they  must  not  try  to  resist  the  sharp  machetes. 
Then  the  Indians  set  to  work.  They  fell  a  tree,  bind  it  with  light 
ropes  woven  from  the  wild  cotton,  and  haul  it  to  its  place.  That 
is  all  for  the  day.    They  play  in  the  sun,  do  a  little  hunting,  or 


32  THE  ANDES  OF  SOUTHERN  PERU 

look  over  the  agent's  house,  touching  everything,  talking  little, 
exclaiming  much.  They  dip  their  wet  fingers  in  the  sugar  bowl  and 
taste,  turn  salt  out  upon  their  hands,  hold  colored  solutions  from 
the  medicine  chest  up  to  the  light,  and  pull  out  and  push  in  the 
corks  of  the  bottles.  At  the  end  of  a  month  or  two  the  house  is 
done.    Then  they  gather  their  women  and  babies  together  and  say : 

"Now  we  go,"  without  asking  if  the  work  corresponds  with  the 
cost  of  the  articles  they  had  bought.  Their  judgment  is  good  how- 
ever. Their  work  is  almost  always  more  valuable  than  the  arti- 
cles.   Then  they  shake  hands  all  around. 

"We  will  come  again,"  they  say,  and  in  a  moment  have  disap- 
peared in  the  jungle  that  overhangs  the  trail. 

With  such  labor  the  Compaiiia  Gomera  de  Mainique  can  do 
something,  but  it  is  not  much.  The  regular  seasonal  tasks  of  road- 
building  and  rubber-picking  must  be  done  by  imported  labor.  This 
is  secured  chiefly  at  Abancay,  where  live  groups  of  plateau  In- 
dians that  have  become  accustomed  to  the  warm  climate  of  the 
Abancay  basin.  They  are  employed  for  eight  or  ten  months  at  an 
average  rate  of  fifty  cents  gold  per  day,  and  receive  in  addition 
only  the  simplest  articles  of  food. 

At  the  end  of  the  season  the  gang  leaders  are  paid  a  gratifica- 
cion,  or  bonus,  the  size  of  which  depends  upon  the  amount  of  rub- 
ber collected,  and  this  in  turn  depends  upon  the  size  of  the  gang 
and  the  degree  of  willingness  to  work.  In  the  books  of  the  com- 
pany I  saw  a  record  of  (jratificaciones  running  as  high  as  $600 
in  gold  for  a  season's  work. 

Some  of  the  laborers  become  sick  and  are  cared  for  by  the 
agent  until  they  recover  or  can  be  sent  back  to  their  homes.  Most 
of  them  have  fever  before  they  return. 

The  rubber  costs  the  company  two  soles  ($1.00)  produced  at 
^';i\('i-«).  Tlic  1\v()  weeks'  1  i';iiis]>()?-la1  ion  to  ( ^izco  costs  three  and 
a  li;ilf  soles  ($1.75)  per  twenty-five  pounds.  The  exported  rubber, 
known  to  tlif  tr;i(l<'  as  Mollendo  rubber,  in  contrast  to  the  finer 
"Par.-i"  rublxT  from  the  lower  Amazon,  is  shipped  to  TTamburg. 
The  cost  for  traiiKportation  from  port  to  port  is  $24.00  per  Eng- 
lish ton  (1,010  kilos).    There  is  a  Peruvian  tax  of  8  per  cent  of 


THE  RUBBER  FORESTS  33 

the  net  value  in  Europe,  and  a  territorial  tax  of  two  soles  ($1.00) 
per  hundred  pounds.  All  supplies  except  the  few  vegetables 
grown  on  the  spot  cost  tremendously.  Even  dynamite,  hoes,  cloth- 
ing, rice — to  mention  only  a  few  necessities — must  pay  the  heavy 
cost  of  transportation  after  imposts,  railroad  and  ocean  freight, 
storage  and  agents'  percentages  are  added.  The  effect  of  a  dis- 
turbed market  is  extreme.  When,  in  1911,  the  price  of  rubber  fell 
to  $1.50  a  kilo  at  Hamburg  the  company  ceased  exporting.  When  it 
dropped  still  lower  in  1912  production  also  stopped,  and  it  is  still 
doubtful,  in  view  of  the  growing  competition  of  the  East-Indian 
plantations  with  their  cheap  labor,  whether  operations  w411  ever  be 
resumed.  Within  tliree  years  no  less  than  a  dozen  large  com- 
panies in  eastern  Peru  and  Bolivia  have  ceased  operations.  In  one 
concession  on  the  Madre  de  Dios  the  withdrawal  of  the  agents  and 
laborers  from  the  posts  turned  at  last  into  flight,  as  the  forest 
Indians,  on  learning  the  company's  policy,  rapidly  ascended  the 
river  in  force,  committing  numerous  depredations.  The  great 
war  has  also  added  to  the  difficulties  of  production. 

Facts  like  these  are  vital  in  the  consideration  of  the  future  of 
the  Amazon  basin  and  especially  its  habitability.  It  was  the 
dream  of  Humboldt  that  great  cities  should  arise  in  the  midst  of 
the  tropical  forests  of  the  Amazon  and  that  the  whole  lowland 
plain  of  that  river  basin  should  become  the  home  of  happy  mil- 
lions. Humboldt's  vision  may  have  been  correct,  though  a  hun- 
dred years  have  brought  us  but  little  nearer  its  realization.  Now, 
as  in  the  past  four  centuries,  man  finds  his  hands  too  feeble  to  con- 
trol the  great  elemental  forces  which  have  shaped  history.  The 
most  he  can  hope  for  in  the  next  hundred  years  at  least  is  the 
ability  to  dodge  Nature  a  little  more  successfully,  and  here  and 
there  by  studies  in  tropical  hygiene  and  medicine,  by  the  substi- 
tution of  water-power  for  human  energy,  to  carry  a  few  of  the  out- 
posts and  prepare  the  way  for  a  final  assault  in  the  war  against 
the  hard  conditions  of  climate  and  relief.  We  hear  of  the  Madeira- 
Mamore  railroad,  200  miles  long,  in  the  heart  of  a  tropical  forest 
and  of  the  commercial  revolution  it  will  bring.  Do  we  realize  that 
the  forest  which  overhangs  the  rails  is  as  big  as  the  w^hole  plain 


34  THE  ANDES  OF  SOUTHERN  PERU 

between  the  Rockies  and  tlie  Appalachians,  and  that  the  proposed 
line  would  extend  only  as  far  as  from  St.  Louis  to  Kansas  City, 
or  from  Galveston  to  New  Orleans? 

Even  if  twenty  whites  were  eager  to  go  where  now  there  is  but 
one  reluctant  pioneer,  we  should  still  have  but  a  halting  develop- 
ment on  account  of  the  scarcity  of  labor.  When,  three  hundred 
years  ago,  the  Isthmus  of  Panama  stood  in  his  way,  Gomara 
wrote  to  his  king:  "There  are  mountains,  but  there  are  also 
hands,"  as  if  men  could  be  conjured  up  from  the  tropical  jungle. 
From  that  day  to  this  the  scarcity  of  labor  has  been  the  chief  dif- 
ficulty in  the  lowland  regions  of  tropical  South  America.  Even 
when  medicine  shall  have  been  advanced  to  the  point  where  resi- 
dence in  the  tropics  can  be  made  safe,  the  Amazon  basin  will  lack 
an  adequate  supply  of  workmen.  Where  Humboldt  saw  thriving 
cities,  the  population  is  still  less  than  one  to  the  square  mile  in 
an  area  as  large  as  fifteen  of  our  Mississippi  Valley  states.  We 
hear  much  about  a  rich  soil  and  little  about  intolerable  insects; 
the  climate  favors  a  good  growth  of  vegetation,  but  a  man  can 
starve  in  a  tropical  forest  as  easily  as  in  a  desert;  certain  tribu- 
taries of  the  Negro  are  bordered  by  rich  rubber  forests,  yet  not 
a  single  Indian  hut  may  be  found  along  their  banks.  Will  men 
of  the  white  race  dig  up  the  rank  vegetation,  sleep  in  grass  ham- 
mocks, live  in  the  hot  and  humid  air,  or  will  they  stay  in  the  cooler 
regions  of  the  north  and  south'?  Will  they  rear  children  in  the 
temperate  zones,  or  bury  them  in  the  tropics'? 

What  Gorgas  did  for  Panama  was  done  for  intelligent  people. 
Can  it  be  duplicated  in  the  case  of  ignorant  and  stupid  laborers? 
Shall  the  white  man  with  wits  fight  it  out  with  Nature  in  a  tropical 
forest,  or  fight  it  out  with  his  equals  under  better  skies? 

The  tropics  must  be  won  by  strong  hands  of  the  lowlier  classes 
who  are  ignorant  or  careless  of  hygiene,  and  not  by  the  khaki-clad 
robust  young  men  like  those  who  work  at  Panama.  Tropical  medi- 
cine can  do  something  for  these  folk,  but  it  cannot  do  much.  And 
wo  ('anTif)t  Kurround  every  laborer's  cottage  with  expensive 
scroons,  oilod  difclics,  and  well-kept  lawns.  There  is  a  practical 
optimism  and  a  sfntimfTilnl  optimism.    The  one  is  based  on  facts; 


THE  RUBBER  FORESTS  36 

the  other  on  assumptions.  It  is  pleasant  to  think  that  the  tropical 
forest  may  be  conquered.  It  is  nonsense  to  say  that  we  are  now 
conquering  it  in  any  comprehensive  and  permanent  way.  That 
sort  of  conquest  is  still  a  dream,  as  when  Humboldt  wrote  over  a 
hundred  years  ago. 


CHAPTER  IV 
THE  FOREST  INDIANS 

The  people  of  a  tropical  forest  live  under  conditions  not  unlike 
those  of  the  desert.  The  Sahara  contains  2,000,000  persons  within 
its  borders,  a  density  of  one-half  to  the  square  mile.  This  is  al- 
most precisely  the  density  of  population  of  a  tract  of  equivalent 
size  in  the  lowland  forests  of  South  America.  Like  the  oases 
groups  in  the  desert  of  aridity  are  the  scattered  groups  along  the 
river  margins  of  the  forest.  The  desert  trails  run  from  spring  to 
spring  or  along  a  valley  floor  where  there  is  seepage  or  an  inter- 
mittent stream;  the  rivers  are  the  highways  of  the  forest,  the 
flowing  roads,  and  away  from  them  one  is  lost  in  as  true  a  sense 
as  one  may  be  lost  in  the  desert. 

A  man  may  easily  starve  in  the  tropical  forest.  Before  start- 
ing on  even  a  short  journey  of  two  or  three  days  a  forest  Indian 
stocks  his  canoe  with  sugar  cane  and  yuca  and  a  little  parched 
com.  He  knows  the  settlements  as  well  as  his  desert  brother 
knows  the  springs.  The  Pahute  Indian  of  Utah  lives  in  the  irri- 
gated valleys  and  makes  annual  excursions  across  the  desert  to 
the  distant  mountains  to  gather  the  seeds  of  the  nut  pine.  The 
Machiganga  lives  in  the  hills  above  the  Urubamba  and  annually 
comes  down  through  the  forest  to  the  river  to  fish  during  the  dry 
season. 

The  Machigangas  are  one  of  the  important  tribes  of  the  Ama- 
zon basin.  Though  they  are  dispersed  to  some  extent  upon  the 
plains  their  chief  groups  are  scattered  through  the  heads  of  a 
large  num])or  of  valleys  near  the  eastern  border  of  the  Andes. 
Chief  among  tlie  valleys  they  occupy  are  the  Pilcopata,  Tone, 
Pini-pifii,  Yavero,  Yuyato,  Sliirinoiri,  Ticumpiuea,  Timpia,  and 
Camisca  (Fig.  20.'?).  Tn  their  distribution,  in  their  relations  with 
each  other,  in  their  manner  of  life,  and  to  some  extent  in  their 
personal  traits,  they  display  characteristics  strikingly  like  those 


THE  FOREST  INDIANS  37 

seen  in  desert  peoples.  Though  the  forest  that  surrounds  them 
suggests  plenty  and  the  rivers  the  possibility  of  free  movement 
with  easy  intercourse,  the  struggle  of  life,  as  in  the  desert,  is 
against  useless  things.  Travel  in  the  desert  is  a  conflict  with  heat 
and  aridity;  but  travel  in  the  tropic  forest  is  a  struggle  against 
space,  heat,  and  a  superabundant  and  all  but  useless  vegetation. 

The  Machigangas  are  one  of  the  subtribes  of  the  Campas  In- 
dians, one  of  the  most  numerous  groups  in  the  Amazon  Valley.  It 
is  estimated  that  there  are  in  all  about  14,000  to  16,000  of  them. 
Each  subtribe  numbers  from  one  to  four  thousand,  and  the  terri- 
tory they  occupy  extends  from  the  limits  of  the  last  plantations— 
for  example,  Eosalina  in  the  Urubamba  Valley — downstream  be- 
yond the  edge  of  the  plains.  Among  them  three  subtribes  are  still 
hostile  to  the  whites:  the  Cashibos,  the  Chonta  Campas,  and  the 
Campas  Bravos. 

In  certain  cases  the  Cashibos  are  said  to  be  anthropophagous, 
in  the  belief  that  they  will  assume  the  strength  and  intellect  of 
those  they  eat.  This  group  is  also  continuously  at  war  with  its 
neighbors,  goes  naked,  uses  stone  hatchets,  as  in  ages  past,  be- 
cause of  its  isolation  and  unfriendliness,  and  defends  the  entrances 
to  the  tribal  huts  with  dart  and  traps.  The  Cashibos  are  diminish- 
ing in  numbers  and  are  now  scattered  through  the  valley  of  the 
Gran  Pajonal,  the  left  bank  of  the  Pachitea,  and  the  Pampa  del 
Sacramento.^ 

The  friendliest  tribes  live  in  the  higher  valley  heads,  where 
they  have  constant  communication  with  the  whites.  The  use  of  the 
bow  and  arrow  has  not,  however,  been  discontinued  among  them, 
in  spite  of  the  wide  introduction  of  the  old-fashioned  muzzle-load- 
ing shotgun,  which  they  prize  much  more  highly  than  the  latest 
rifle  or  breech-loading  shotgun  because  of  its  simplicity  and  cheap- 

'  The  Casliibos  of  the  Pachitea  are  the  tribe  for  whom  the  Piros  besought  Herndon 
to  produce  "  some  great  and  infectious  disease "  which  could  be  carried  up  the  river 
and  lot  loose  amongst  them  (Herndon,  Exploration  of  the  Valley  of  the  Amazon, 
Washington,  1854,  Vol.  1,  p.  196).  This  would-be  artfulness  suggests  itself  as  some- 
thing of  a  match  against  the  cunning  of  the  Cashibos  whom  rumor  reports  to  imitate 
the  sounds  of  the  forest  animals  with  such  skill  as  to  betray  into  their  hands  the 
hunters  of  other  tribes  (see  von  Tschudi,  Travels  in  Peru  During  the  Years  1838-1842, 
translated  from  the  German  by  Thomasina  Eoss,  New  York,   1849,  p.  404). 


38  THE  ANDES  OF  SOUTHERN  PERU 

ness.  Accidents  are  frequent  among  them  owing  to  the  careless 
use  of  tire-arms.  On  our  last  day's  journey  on  the  Urubamba 
above  the  mouth  of  the  Timpia  one  of  our  Indian  boys  dropped  his 
canoe  pole  on  the  hammer  of  a  loaded  shotgun,  and  not  only  shot 
his  own  fingers  to  pieces,  but  gravely  wounded  his  father  (Fig.  2). 
In  spite  of  his  suffering  the  old  chief  directed  our  work  at  the 
canoe  and  even  was  able  to  tell  us  the  location  of  the  most  favora- 
ble channel.  Though  the  night  that  followed  was  as  black  as  ink, 
with  even  the  stars  obscured  by  a  rising  storm,  his  directions 
never  failed.  'We  poled  our  way  up  five  long  rapids  without  spe- 
cial difficulties,  now  working  into  the  lee  of  a  rock  whose  location 
he  knew  within  a  few  yards,  now  paddling  furiously  across  the 
channel  to  catch  the  upstream  current  of  an  eddy. 

The  principal  groups  of  Machigangas  live  in  the  middle  Uru- 
bamba and  its  tributaries,  the  Yavero,  Yuyato,  Shirineiri,  Ticum- 
pinea,  Timpia,  Pachitea,  and  others.  There  is  a  marked  difference 
in  the  use  of  the  land  and  the  mode  of  life  among  the  different 
groups  of  this  subtribe.  Those  who  live  in  the  lower  plains  and 
river  ''playas,"  as  the  patches  of  flood  plain  are  called,  have  a  sin- 
gle permanent  dwelling  and  alternately  fish  and  hunt.  Those  that 
live  on  hill  farms  have  temporary  reed  huts  on  the  nearest  sand- 
bars and  spend  the  best  months  of  the  dry  season — April  to  Oc- 
tober— in  fishing  and  drying  fish  to  be  carried  to  their  mountain 
homes  (Fig.  21).  Some  families  even  duplicate  chacras  or  farms 
at  tlie  river  bank  and  grow  yuca  and  sugar  cane.  In  latter  years 
smallpox,  malaria,  and  the  rubber  hunters  have  destroyed  many 
of  the  river  villages  and  driven  the  Indians  to  permanent  resi- 
dence in  the  hills  or.  wliero  raids  occur,  along  secret  trails  to  hid- 
den camps. 

Thoir  system  of  agriculture  is  strikingly  adapted  to  some  im- 
})oi-faiit  features  of  tropical  soil.  I'lie  tlilii  hillside  soils  of  the 
region  are  but  poorly  stocked  with  luunus,  even  in  their  virgin 
condition,  [''alien  trees  and  foliage  decay  so  quickly  that  the  layer 
of  for<'st  mf)ld  is  exceedingly  thin  and  the  little  that  is  incor- 
porated in  the  soil  is  confined  to  a  shallow  surface  layer.  To  meet 
these  special  conditions  tlie   Indian  makes  new  clearings  by  gir- 


THE  FOREST  INDIANS  39 

dling  and  burning  the  trees.  When  the  soil  becomes  worn  out  and 
the  crops  diminish,  the  old  clearing  is  abandoned  and  allowed  to 
revert  to  natural  growth  and  a  new  farm  is  planted  to  corn  and 
joica.  The  population  is  so  scattered  and  thin  that  the  land  assign- 
ment system  current  among  the  plateau  Indians  is  not  practised 
among  the  Machigangas.  Several  families  commonly  live  together 
and  may  be  separated  from  their  nearest  neighbors  by  many  miles 
of  forested  mountains.  The  land  is  free  for  all,  and,  though  some 
heavy  labor  is  necessary  to  clear  it,  once  a  small  patch  is  cleared 
it  is  easy  to  extend  the  tract  by  limited  annual  cuttings.  Local 
tracts  of  naturally  unforested  land  are  rarely  planted,  chiefly  be- 
cause the  absence  of  shade  has  allowed  the  sun  to  burn  out  the 
limited  humus  supply  and  to  prevent  more  from  accumulating. 
The  best  soil  of  the  mountain  slopes  is  found  where  there  is  the 
heaviest  growth  of  timber,  the  deepest  shade,  the  most  humus,  and 
good  natural  drainage.  It  is  the  same  on  the  playas  along  the 
river ;  the  recent  additions  to  the  flood  plain  are  easy  to  cultivate, 
but  they  lack  humus  and  a  fine  matrix  which  retains  moisture 
and  prevents  drought  or  at  least  physiologic  drjTiess.  Here,  too, 
the  timbered  areas  or  the  cane  swamps  are  always  selected  for 
planting. 

The  traditions  of  the  Machigangas  go  back  to  the  time  of  the 
Inca  conquest,  when  the  forest  Indians,  the  "Antis,"  were  subju- 
gated and  compelled  to  pay  tribute.-  When  the  Inca  family  itself 
fled  from  Cuzco  after  the  Spanish  Conquest  and  sought  refuge  in 
the  wilderness  it  was  to  the  Machiganga  country  that  they  came  by 
way  of  the  Vilcabamba  and  Pampaconas  Valleys.  Afterward  came 
the  Spaniards  and  though  they  did  not  exercise  governmental  au- 

^  The  early  chronicles  contain  several  references  to  Antisuyu  and  the  Antis. 
Garcilaso  de  la  Vega's  description  of  the  Inca  conquests  in  Antisuyu  are  well  known 
(Royal  Commentaries  of  the  Yncas,  Book  4,  Chapters  16  and  17,  Hakluyt  Soc.  Pubis., 
1st  Ser.,  No.  41,  1869  and  Book  7,  Chapters  13  and  14,  No.  45,  1871).  Salcamayhua 
who  also  chronicles  these  conquests  relates  a  legend  concerning  the  tribute  payers 
of  the  eastern  valleys.  On  one  occasion,  he  says,  three  hundred  Antis  came  laden  with 
gold  from  Opatari.  Their  arrival  at  Cuzco  was  coincident  with  a  killing  frost  that 
ruined  all  the  crops  of  the  basin  whence  the  three  hundred  fortunates  were  ordered 
with  their  gold  to  the  top  of  the  high  hill  of  Pachatucsa  (Pachatusun)  and  there 
buried  with  it  (An  Account  of  the  Antiquities  of  Peru,  Hakluyt  Soc  Pubis  1st 
Ser.,   No.   48,   1873). 


40  THE  ANDES  OF  SOUTHERN  PERU 

thority  over  the  forest  Indians  they  had  close  relations  mth  them. 
Land  grants  were  made  to  white  pioneers  for  special  services  or 
through  sale  and  with  the  land  often  went  the  right  to  exploit  the 
people  on  it.  Some  of  the  concessions  were  owned  by  people  w^ho 
for  generations  knew  nothing  save  by  hearsay  of  the  Indians  who 
dwelt  in  the  great  forests  of  the  valleys.  In  later  years  they  have 
been  exploring  their  lands  and  establishing  so-called  relations 
whereby  the  savage  ''buys"  a  dollar's  w^orth  of  powder  or  knives 
for  whatever  number  of  dollars'  worth  of  rubber  the  o\\Tier  may 
care  to  extract  from  him. 

The  forest  Indian  is  still  master  of  his  lands  throughout  most 
of  the  Machiganga  country.  He  is  cruelly  enslaved  at  the  rubber 
posts,  held  by  the  loose  bonds  of  a  desultory  trade  at  others,  and 
in  a  few  places,  as  at  Pongo  de  Mainique,  gives  service  for  both 
love  and  profit,  but  in  many  places  it  is  impossible  to  establish  con- 
trol or  influence.  The  lowland  Indian  never  falls  into  the  abject 
condition  of  his  Quechua  brother  on  the  plateau.  He  is  self-re- 
liant, proud,  and  independent.  He  neither  cringes  before  a  white 
nor  looks  up  to  him  as  a  superior  being.  I  was  greatly  impressed 
by  the  bearing  of  the  first  of  the  forest  tribes  I  met  in  August, 
1911,  at  Santo  Anato.  I  had  built  a  brisk  fire  and  was  enjoying 
its  comfort  when  La  Sama  returned  with  some  Indians  whom  he 
had  secured  to  clear  his  playa.  The  tallest  of  the  lot,  wearing  a 
colored  band  of  deer  skin  around  his  thick  hair  and  a  gaudy  bunch 
of  yellow  feathers  down  his  back,  came  up,  looked  me  squarely  in 
the  eye,  and  asked 

"Tatiry  payta?"  (What  is  your  name?) 

AVhon  1  replied  he  quietly  sat  down  by  the  fire,  helping  himself 
to  the  roasted  corn  I  had  prepared  in  the  hot  ashes.  A  few  days 
later  when  we  came  to  the  head  of  a  rapid  I  was  busy  sketching-in 
my  topographic  map  and  did  not  hoar  his  twice  repeated  request 
to  leave  the  ])oa1  wliilc  flic  |)ar<y  reconnoiterod  ihc  rapid.  Watch- 
ing his  opportiniily  he  came  alongside  from  the  rear — he  was 
steersman — and,  turning  just  as  he  was  leaving  the  boat,  gave  me 
a  whack  in  the  forehead  with  his  open  palm.  La  Sama  saw  the 
motion  and  protested.    The  surly  answer  was: 


THE  FOREST  INDIANS  41 

"I  twice  asked  him  to  get  out  and  he  didn't  move.  What  does 
he  think  we  run  the  canoe  to  the  bank  for?" 

To  him  the  making  of  a  map  was  inexplicable ;  I  was  merely  a 
stupid  white  person  who  didn't  know  enough  to  get  out  of  a  canoe 
when  told! 

The  plateau  Indian  has  been  kicked  about  so  long  that  all  his 
independence  has  been  destroyed.  His  goods  have  been  stolen,  his 
services  demanded  without  recompense,  in  many  places  he  has  no 
right  to  land,  and  his  few  real  rights  are  abused  beyond  belief.  The 
difference  between  him  and  the  forest  Indian  is  due  quite  largely 
to  differences  of  environment.  The  plateau  Indian  is  agricultural, 
the  forest  Indian  nomadic  and  in  a  hunting  stage  of  development ; 
the  unforested  plateau  offers  no  means  for  concealment  of  person 
or  property,  the  forest  offers  hidden  and  difficult  paths,  easy 
means  for  concealment,  for  ambush,  and  for  wide  dispersal  of  an 
afflicted  tribe.  The  brutal  white  of  the  plateau  follows  altogether 
different  methods  when  he  finds  himself  in  the  Indian  country,  far 
from  military  assistance,  surrounded  by  fearless  savages.  He 
may  cheat  but  he  does  not  steal,  and  his  brutality  is  always  care- 
fully suited  to  both  time  and  place. 

The  Machigangas  are  now  confined  to  the  forest,  but  the  limits 
of  their  territory  were  once  farther  upstream,  where  they  were  in 
frequent  conflict  with  the  plateau  Indians.  As  late  as  1835,  ac- 
cording to  General  Miller,^  they  occupied  the  land  as  far  upstream 
as  the  "Encuentro"  (junction)  of  the  Urubamba  and  the  Yanatili 
(Fig.  53).  Miller  likewise  notes  that  the  Chuntaguirus,  "a 
superior  race  of  Indians"  who  lived  ''toward  the  Maraiion," 
came  up  the  river  "200  leagues"  to  barter  with  the  people 
thereabouts. 

"They  bring  parrots  and  other  birds,  monkeys,  cotton  robes 
white  and  painted,  w^ax  balsams,  feet  of  the  gran  bestia,  feather 
ornaments  for  the  head,  and  tiger  and  other  skins,  which  they  ex- 
change for  hatchets,  knives,  scissors,  needles,  buttons,  and  any 
sort  of  glittering  bauble." 


'  Notice  of  a  Journey  to  the  Northward  and  also  to  the  Northeastward  of  Cuzco. 
Royal   Geog.    Soc.   Journ.,   Vol.   6,    1836,   pp.    174-186. 


42  THE  ANDES  OF  SOUTHERN  PERU 

On  their  yearly  excursions  they  traveled  in  a  band  numbering 
from  200  to  300,  since  at  the  mouth  of  the  Paucartambo  (Yavero) 
they  were  generally  set  upon  by  the  Pucapacures.  The  journey 
upstream  required  three  months;  with  the  current  they  returned 
home  in  fifteen  days. 

Their  place  of  meeting  at  the  mouth  of  the  Yanatili  was  a 
response  to  a  long  strip  of  grassland  that  extends  do^vn  the  deep 
and  dry  Urubamba  Valley,  as  shown  in  Figs.  53-B  and  55.  The 
wet  forests,  in  which  the  Machigangas  live,  cover  the  hills  back 
of  the  valley  plantations;  the  belt  of  dry  grassland  terminates 
far  within  the  general  limits  of  the  red  man's  domain  and  only 
2,000  feet  above  the  sea.  It  is  in  this  strip  of  low  grassland  that 
on  the  one  hand  the  highland  and  valley  dwellers,  and  on  the  other 
the  Indians  of  the  hot  forested  valleys  and  the  adjacent  lowland 
found  a  convenient  place  for  barter.  The  same  physiographic 
features  are  repeated  in  adjacent  valleys  of  large  size  that  drain 
the  eastern  aspect  of  the  Peruvian  Andes,  and  in  each  case  they 
have  given  rise  to  the  periodic  excursions  of  the  trader. 

These  annual  journeys  are  no  longer  made.  The  planters  have 
crept  down  valley.  The  two  best  playas  below  Rosalina  are  now 
being  cleared.  Only  a  little  space  remains  between  the  lowest  val- 
ley plantations  and  the  highest  rubber  stations.  Furthermore,  the 
Indians  have  been  enslaved  by  the  rubber  men  from  the  Ucayali. 
'i'he  Macliigangas,  many  of  whom  are  runaway  peons,  will  no 
longer  take  cargoes  down  valley  for  fear  of  recapture.  They  have 
tlio  cautious  spirit  of  fugitives  except  in  their  remote  valleys. 
'I'luTc  they  aro  secure  and  now  and  llicu  reassert  their  old  spirit 
wiicn  ;i  lawless  trader  hies  to  browbeat  them  into  an  unprofitable 
trado.  .\lso,  they  are  yielding  to  the  alluring  call  of  the  planter. 
At  Santo  Ana  to  they  are  clearing  a  playa  in  exchange  for  am- 
nnniition,  machetes,  brandy,  and  baubles.  They  no  longer  make 
.'iniiiial  excursions  to  get  these  things.  They  have  only  to  call  at 
the  nearest  jdantation.  There  is  always  a  wolf  before  the  door  of 
tin'  planter — the  lack  of  labor.  \ot,  as  on  every  frontier,  he  turns 
wolf  himsolf  when  the  lambs  come,  and  without  shame  takes  a 
week's   work    foi'  a   ])e!niy  mirror,  or,  woi'se  still,   supplies  them 


THE  FOREST  INDIANS  43 

with  firewater,  for  that  will  surely  bring  them  back  to  him.  Since  \ 
this  is  expensive  they  return  to  their  tribal  haunts  with  nothing 
except  a  debauched  spirit  and  an  appetite  from  which  they  can- 
not run  away  as  they  did  from  their  task  masters  in  the  rubber 
forest.  Hence  the  vicious  circle :  more  brandy,  more  labor ;  more 
labor,  more  cleared  land;  more  cleared  land,  more  brandy;  more 
brandy,  less  Indian,  But  by  that  time  the  planter  has  a  large 
sugar  estate.  Then  he  can  begin  to  buy  the  more  expensive 
plateau  labor,  and  in  turn  debauch  it. 

Nature  as  well  as  man  works  against  the  scattered  tribes  of 
Machigangas  and  their  forest  kinsmen.  Their  country  is  exceed- 
ingly broken  by  ramifying  mountain  spurs  and  valleys  overhung 
with  cliffs  or  bordered  by  bold,  wet,  fern-clad  slopes.  It  is 
useless  to  try  to  cut  your  way  by  a  direct  route  from  one 
point  to  another.  The  country  is  mantled  with  heavy  forest. 
You  must  follow  the  valleys,  the  ancient  trails  of  the  people.  The 
larger  valleys  offer  smooth  sand-bars  along  the  border  of  which 
canoes  may  be  towed  upstream,  and  there  are  little  cultivated 
places  for  camps.  But  only  a  few  of  the  tribes  live  along  them, 
for  they  are  also  more  accessible  to  the  rubbermen.  The  smaller 
valleys,  difficult  of  access,  are  more  secure  and  there  the  tribal  rem- 
nants live  today.  While  the  broken  country  thus  offers  a  refuge 
to  fugitive  bands  it  is  the  broken  country  and  its  forest  cover  that 
combine  to  break  up  the  population  into  small  groups  and  keep 
them  in  an  isolated  and  quarrelsome  state.  Chronic  quarreling 
is  not  only  the  product  of  mere  lack  of  contact.  It  is  due  to  many 
causes,  among  which  is  a  union  of  the  habit  of  migration  and 
divergent  tribal  speech.  Every  tribe  has  its  own  peculiar  words 
in  addition  to  those  common  to  the  group  of  tribes  to  which  it  be- 
longs. Moreover  each  group  of  a  tribe  has  its  distinctive  words. 
I  have  seen  and  used  carefully  prepared  vocabularies — no  two  of 
which  are  alike  throughout.  They  serve  for  communication  with 
only  a  limited  number  of  families..  These  peculiarities  increase 
as  experiences  vary  and  new  situations  call  for  additions  to  or 
changes  in  their  vocabularies,  and  when  migrating  tribes  meet 
their  speech  may  be  so  unlike  as  to  make  communication  difficult. 


44;  THE  ANDES  OF  SOUTHERN  PERU 

Thus  arise  suspicion,  misunderstanding,  plunder,  and  chronic  war. 
Had  they  been  a  united  people  their  defense  of  their  rough  coun- 
try might  have  been  successful.  The  tribes  have  been  divided  and 
now  and  again,  to  get  firearms  and  ammunition  Avith  which  to  raid 
a  neighbor,  a  tribe  has  joined  its  fortunes  to  those  of  vagrant  rub- 
ber pickers  only  to  find  in  time  that  its  women  were  debased,  its 
members  decimated  by  strange  and  deadly  diseases,  and  its  old 
morality  undermined  by  an  insatiable  desire  for  strong  drink.* 
/The  Indian  loses  whether  with  the  white  or  against  him. 

The  forest  Indian  is  held  by  his  environment  no  less  strongly 
than  the  plateau  Indian.  We  hear  much  about  the  restriction  of 
the  plateau  dweller  to  the  cool  zone  in  which  the  llama  may  live. 
/  As  a  matter  of  fact  ho  lives  far  below  the  cool  zone,  where  he  no 
longer  depends  upon  the  llama  but  rather  upon  the, mule  for  trans- 
port. The  limits  of  his  range  correspond  to  the  limits  of  the 
grasslands  in  the  dry  valley  pockets  already  described  (p.  42),  or 
on  the  drier  mountain  slopes  below  the  zone  of  heaviest  rainfall 
(Fig.  54).  It  is  this  distribution  that  brought  him  into  such  in- 
timate contact  with  the  forest  Indian.  The  old  and  dilapidated 
coca  terraces  of  the  Quechuas  above  the  Yanatili  almost  overlook 
the  forest  patches  where  the  Machigangas  for  centuries  built  their 
rude  huts.  A  good  deal  has  been  written  about  the  attempts  of 
the  Incas  to  extend  their  rule  into  this  forest  zone  and  about  the 
failure  of  these  attempts  on  account  of  the  tropical  climate.  But 
llie  forest  Indian  was  held  by  bonds  equally  secure.  The  cold  cli- 
mate of  the  plateau  repelled  him  as  it  does  today.  His  haunts  are 
flic  liot  valleys  where  he  need  wear  only  a  wild-cotton  sliirt  or 
where  ho  may  go  naked  altogether.  That  he  raided  the  lands  of 
tho  plateau  Indian  is  certain,  l)ut  he  could  never  displace  him. 
Only  along  the  common  borders  of  their  domains,  where  the 
climates  of  two  zoiU'S  merged  iiilo  each  otlici',  couhl  Ihc  forest 
Indiiin    and    I  lie    jihitc.-m    Indian    seriously    dispute    each    otlier's 


•  Wnllc  Htatcfl  (Lo  IVtoii  Kcononiiqdc,  I'liriH,  1007,  p.  207)  that  the  Conibos,  a 
trilKf  nf  tlio  rpnynli,  make  nniiual  corrcriaa  or  raids  during;  Uio  months  of  July, 
August,  and  Sfptcmlicr,  Ihnt  is  during  the  season  of  low  water.  Over  snvon  hundred 
canoes  are  said  to  participiit)-  and  the  captives  secured  nre  sold  to  rubber  exploitcra, 
who,   indeed,   freqtiently  nid   in   the  orpanizntion  of  the  rnids. 


THE  FOREST  INDIANS  45 

claims  to  the  land.     Here  was  endless  conflict  but  only  feeble 
trade  and  only  the  most  minute  exchanges  of  cultural  elements. 

Even  had  they  been  as  brothers  they  would  have  had  little  in- 
centive to  borrow  cultural  elements  from  each  other.  The  forest 
dweller  requires  bow  and  arrow;  the  plateau  dweller  requires  a 
hoe.  There  are  fish  in  the  warm  river  shallows  of  the  forested 
zone;  llamas,  vicuiia,  vizcachas,  etc.,  are  a  partial  source  of  food 
supply  on  the  plateau.  Coca  and  potatoes  are  the  chief  products 
of  the  grassy  mountain  slopes ;  yuca,  corn,  bananas,  are  the  chief 
vegetable  foods  grown  on  the  tiny  cultivated  patches  in  the  forest. 
The  plateau  dweller  builds  a  thick-walled  hut;  the  valley  dweller 
a  cane  shack.  So  unlike  are  the  two  environments  that  it  would 
be  strange  if  there  had  been  a  mixture  of  racial  types  and  cul- 
tures. The  slight  exchanges  that  were  made  seem  little  more  than 
accidental.  Even  today  the  Machigangas  who  live  on  the  highest 
slopes  own  a  few  pigs  obtained  from  Quechuas,  but  they  never 
eat  their  flesh ;  they  keep  them  for  pets  merely.  I  saw  not  a  single 
woolen  article  among  the  Indians  along  the  Urubamba  whereas 
Quechuas  with  woolen  clothing  were  going  back  and  forth  regu- 
larly. Their  baubles  were  of  foreign  make;  likewise  their  few 
hoes,  likewise  their  guns. 

They  clear  the  forest  about  a  wild-cotton  tree  and  spin  and 
weave  the  cotton  fiber  into  sacks,  cords  for  climbing  trees  when 
they  wish  to  chase  a  monkey,  ropes  for  hauling  their  canoes,  shirts 
for  the  married  men  and  women,  colored  head-bands,  and  fish  nets. 
The  slender  strong  bamboo  is  gathered  for  arrows.  The  chunta 
palm,  like  bone  for  hardness,  supplies  them  with  bows  and  ar- 
row heads.  The  brilliant  red  and  yellow  feathers  of  forest  birds, 
also  monkey  bones  and  teeth,-  are  their  natural  ornaments.  Their 
life  is  absolutely  distinct  from  that  of  their  Quechua  neighbors. 
Little  wonder  that  for  centuries  forest  and  plateau  Indians  have 
been  enemies  and  that  their  cultures  are  so  distinct,  for  their 
environment  everywhere  calls  for  unlike  modes  of  existence  and 
distinct  cultural  development. 


CHAPTER  V 

THE  COUNTRY  OF  THE  SHEPHERDS 

The  lofty  mountain  zones  of  Peru,  the  high  bordering  valleys, 
and  the  belts  of  rolling  plateau  between  are  occupied  by  tribes  of 
shepherds.     In  that  cold,  inhospitable  region  at  the  top  of  the 
country  are  the  highest  permanent  habitations  in  the  world — 
17,100  feet  (5,210  m.) — the  loftiest  pastures,  the  greatest  degree 
of  adaptation  to  combined  altitude  and  frost.   Jt  is  here  only  a 
step  from  Greenland  to  Arcady.    Nevertheless  it  is  Greenland  that 
has  the  people.    Why  do  they  shun  Arcady?    To  the  traveler  from 
the  highlands  the  fertile  valleys  between  5,000  and  8,000  feet  (1,500 
to  2,5U0  m.)  seem  like  the  abode  of  friendly  spirits  to  whose  charm 
the  highland  dweller  must  yield.     Every  pack-train  from  valley 
to  highland  carries  luxury  in  the  form  of  fruit,  coca,  cacao,  and 
sugar.    One  would  think  that  every  importation  of  valley  products 
would  be  followed  by  a  wave  of  migration  from  highland  to  val- 
ley. fOn  the  contrary  the  highland  people  have  clung  to  their  lofty 
pastures  for  unnumbered  centuries.    Until  the  Conquest  the  last 
outposts  of  the  Incas  toward  the  east  were  the  grassy  ridges  that 
terminate  a  few  thousand  feet  below  the  timber  line. 

In  tliis  natural  grouping  of  the  people  where  does  choice  or 
blind  prejudice  or  instinct  leave  offf  Where  does  necessity  be- 
gin? There  are  answers  to  most  of  these  questions  to  be  found 
in  the  broad  field  of  geographic  comparison.  But  before  we  begin 
comparisons  we  must  study  the  individual  facts  upon  which  they 
rest.  These  facts  are  of  almost  every  conceivable  variety.  They 
range  in  iiiiport.incc  tioiii  a  liumble  shepherd's  stone  corral  on  a 
mountain  slope  to  a  thickly  settled  mountain  basin.  Thoir  in- 
terpretation is  to  be  sought  now  in  the  soil  of  rich  playa  lands, 
now  in  the  fixed  clim.'ific  zones  and  rugged  relief  of  deeply  dis- 
sected, lofty  highlands  in  the  tropics.  Some  of  the  controlling 
factors  are  historical,  others  economic;  still  other  factors  have 


THE  COUNTRY  OF  THE  SHEPHERDS        47 

•exerted  their  influence  through  obscure  psychologic  channels  al- 
most impossible  to  trace.  The  ivJiy  of  man's  distribution  over  the 
earth  is  one  of  the  most  complicated  problems  in  natural  science, 
and  the  solution  of  it  is  the  chief  problem  of  the  modern 
geographer. 

At  first  sight  the  mountain  people  of  the  Peruvian  Andes  seem 
to  be  uniform  in  character  and  in  mode  of  life.  The  traveler's 
first  impression  is  that  the  same  stone-walled,  straw-thatched  type 
of  hut  is  to  be  found  everywhere,  the  same  semi-nomadic  life,  the 
same  degrees  of  poverty  and  filth.  Yet  after  a  little  study  the 
diversity  of  their  lives  is  seen  to  be,  if  not  a  dominating  fact,  at 
least  one  of  surprising  importance.  Side  by  side  with  this  di- 
versity there  runs  a  corresponding  diversity  of  relations  to  their 
physical  environment.  Nowhere  else  on  the  earth  are  greater  phys- 
ical contrasts  compressed  within  such  small  spaces.  If,  there- 
fore, we  accept  the  fundamental  theory  of  geography  that  there  is 
a  general,  necessary,  varied,  and  complex  relation  between  man 
and  the  earth,  that  theory  ought  here  to  find  a  really  vast  num- 
ber of  illustrations.  A  glance  at  the  accompanying  figures  dis- 
closes the  wide  range  of  relief  in  the  Peruvian  Andes.  The  cor- 
responding range  in  climate  and  in  life  therefore  furnishes  an  am- 
ple field  for  the  application  of  the  laws  of  human  distribution. 

In  analyzing  the  facts  of  distribution  we  shall  do  well  to  begin 
with  the  causes  and  effects  of  migration.  Primitive  man  is  in  no 
small  degree  a  wanderer.  His  small  resources  often  require  him 
to  explore  large  tracts.  As  population  increases  the  food  quest 
becomes  more  intense,  and  thus  there  come  about  repeated  emigra- 
tions which  increase  the  food  supply,  extend  its  variety,  and  draw 
the  pioneers  at  last  into  contact  with  neighboring  groups.  The 
farther  back  we  go  in  the  history  of  the  race  the  clearer  it  becomes 
that  migrations  lie  at  the  root  of  much  of  human  development. 
The  raid  for  plunder,  women,  food,  beasts,  is  a  persistent  feature 
of  the  life  of  those  primitive  men  who  live  on  the  border  of  un- 
like regions. 

The  shepherd  of  the  highland  and  the  forest  hunter  of  the 
plains  perforce  range  over  vast  tracts,  and  each  brings  back  to  the 


48  THE  ANDES  OF  SOUTHERN  PERU 

home  group  news  that  confirms  the  tribal  choice  of  habitation  or 
sets  it  in  motion  toward  a  more  desirable  place.  Superstitions 
may  lead  to  flight  akin  to  migration.  Epidemics  may  be  inter- 
preted as  the  work  of  a  malignant  spirit  from  which  men  must  flee. 
War  may  drive  a  defeated  group  into  the  fastnesses  of  a  moun- 
tain forest  where  pursuit  by  stream  or  trail  weakens  the  pursuer 
and  confines  his  action,  thereby  limiting  his  power.  Floods  may 
come  and  destroy  the  cultivated  spots.  Want  or  mere  desire  in  a 
hundred  forms  may  lead  to  movement. 

Even  among  forest  tribes  long  stationary  the  facile  canoe  and 
the  light  household  necessities  may  easily  enable  trivial  causes  to 
develop  the  spirit  of  restlessness.  Pressure  of  population  is  a 
powerful  but  not  a  general  cause  of  movement.  It  may  affect  the 
settled  groups  of  the  desert  oases,  or  the  dense  population  of  fer- 
tile plains  that  is  rooted  in  the  soil.  On  the  other  hand  mere 
whims  may  start  a  nomadic  group  toward  a  new  goal.  Often  the 
goal  is  elusive  and  the  tribe  turns  back  to  the  old  haunts  or  per- 
ishes in  the  shock  of  unexpected  conflict. 

In  the  case  of  both  primitive  societies  and  those  of  a  higher 
order  the  causes  and  the  results  of  migration  are  often  contra- 
dictory. These  will  depend  on  the  state  of  civilization  and  the  ex- 
tremes of  circumstance.  (When  the  desert  blooms  the  farmer  of 
the  Piura  Valley  in  northwestern  Peru  turns  shepherd  and  drives 
his  flocks  of  sheep  and  goats  out  into  the  short-lived  pastures 
of  the  great  pampa  on  the  west.  In  dry  years  he  sends  them 
eastward  into  the  mountains.  "^  The  forest  Indian  of  the  lower  Uru- 
bamba  is  a  fisherman  while  the  river  is  low  and  lives  in  a  reed  hut 
beside  his  cultivated  patch  of  cane  and  yuca.  When  the  floods 
come  he  is  driven  to  the  higher  ground  in  the  hills  where  he  has 
another  cultivated  patch  of  land  and  a  rude  shelter.  To  be  sure, 
these  are  seasonal  Tnigrntioiis,  yet  through  thciii  llic  country  be- 
comes better  known  to  each  new  generation  of  men.  And  each 
generation  snpplics  its  pioneers,  who  drift  into  the  remoter  places 
where  po[)ulation  is  scarce  or  altogether  wanting. 

Dry  years  and  extremely  di-y  years  may  have  op])()site  effects. 
When  moderate  dryness  prevails  the  results  may  be  endurable. 


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THE  COUNTRY  OF  THE  SHEPHERDS        49 

The  oases  become  crowded  with  men  and  beasts  just  when  they 
can  ill  afford  to  support  them.  The  alfalfa  meadows  become  over- 
stocked, and  cattle  become  lean  and  almost  worthless.  But  there 
is  at  least  bare  subsistence.  By  contrast,  if  extreme  and  pro- 
longed drought  prevails,  some  of  the  people  are  driven  forth  to 
more  favored  spots.  At  Vallenar  in  central  Chile  some  of  the 
workmen  in  extreme  years  go  up  to  the  nitrate  pampa;  in  wet 
years  they  return.  When  the  agents  of  the  nitrate  companies  hear 
of  hard  times  in  a  desert  valley  they  offer  employment  to  the 
stricken  people.  It  not  infrequently  happens  that  when  there  are 
droughts  in  desert  Chile  there  are  abundant  rains  in  Argentina 
on  the  other  side  of  the  Cordillera.  There  has  therefore  been  for 
many  generations  an  irregular  and  slight,  though  definite,  shift- 
ing of  population  from  one  side  of  the  mountains  to  the  other  as 
periods  of  drought  and  periods  of  rain  alternated  in  the  tw^o 
regions.  Some  think  there  is  satisfactory  evidence  to  prove  that 
a  number  of  the  great  Mongolian  emigrations  took  place  in  wet 
years  when  pasture  was  abundant  and  when  the  pastoral  nomad 
found  it  easy  to  travel.  On  the  other  hand  it  has  been  urged  that 
the  cause  of  many  emigrations  was  prolonged  periods  of  drought 
when  the  choice  lay  between  starvation  and  flight.  It  is  evident 
from  the  foregoing  that  both  views  may  be  correct  in  spite  of  the 
fact  that  identical  effects  are  attributed  to  opposite  causes. 

It  is  still  an  open  question  whether  security  or  insecurity  is 
more  favorable  for  the  broad  distribution  of  the  Peruvian  Indians 
of  the  mountain  zone  which  forms  the  subject  of  this  chapter.  Cer- 
tainly both  tend  to  make  the  remoter  places  better  known.  Tradi- 
tion has  it  that,  in  the  days  of  intertribal  conflict  before  the  Con- 
quest, fugitives  fled  into  the  high  mountain  pastures  and  lived  in 
hidden  places  and  in  caves.  Life  was  insecure  and  relief  was 
sought  in  flight.  On  the  other  hand  peace  has  brought  security 
to  life.  The  trails  are  now  safe.  A  shepherd  may  drive  his  flock 
anywhere.  He  no  longer  has  any  one  to  fear  in  his  search  for  new 
pastures.  It  would  perhaps  be  safe  to  conclude  that  there  is 
equally  broad  distribution  of  men  in  the  mountain  pastures  in  time 
of  peace  and  in  time  of  war.    There  is,  however,  a  difference  in 


THE  ANDES  OF  SOUTHERN  PERU 


l''i(i.  2') — I{<'gif)niil  diagram  for  tlio  Maritiiiu'  Cordillora  to  hIiow  the  pliysiciil 
rcl.'itionH  in  tlie  district  where  tlic  liighcst  liahitations  in  the  world  are  located.  For 
location,  hcc  Fig.  20.  It  Hhoiild  be  rcinenihcrcd  that  tiie  orient alioii  of  these  dingrama 
\n  generalized.  By  reference  to  Fig.  20  it  will  lie  mcii  Ihat  sunir  jjortions  of  the 
cn-Bt  of  the  .Maritime  Cordillera  run  east  and  west  and  otlurs  iimlli  and  sovitli.  The 
Bami;  18  true  of  the  Cordillera  Vilcapampa,  Fig.  'M't. 


till'  kind  of  distribution.  Jn  timo  of  peace  the  individual  is  safe 
anywhere;  in  time  of  unrest  lie  is  safe  only  when  isolated  and  vir- 
tually concealed.    By  contrast,  the  pcroup  living  iicai-  Die  trails  is 


THE  COUNTRY  OF  THE  SHEPHERDS  51 

scattered  by  plundering  bands  and  war  parties.  The  remote  and 
isolated  group  may  successfully  oppose  the  smaller  band  and  the 
individuals  that  might  reach  the  remoter  regions.  The  fugitive 
group  would  have  nothing  to  fear  from  large  bands,  for  the 
limited  food  supply  would  inevitably  cause  these  to  disintegrate 
upon  leaving  the  main  routes  of  travel.  Probably  the  fullest  ex- 
ploration of  the  mountain  pastures  has  resulted  from  the  alterna- 
tion of  peace  and  war.  The  opposite  conditions  which  these  estab- 
lish foster  both  kinds  of  distribution ;  hence  both  the  remote  group 
life  encouraged  by  war  and  the  individual's  lack  of  restraint  in 


'Note  on  regional  diagrams. — For  the  sake  of  clearness  I  have  classified  the  accom- 
panying facts  of  human  distribution  in  the  country  of  the  shepherds  and  represented 
them  graphically  in  "  regional  "  diagrams,  Figs.  17,  25,  26,  32,  34,  36,  42,  65.  These 
diagrams  are  constructed  on  the  principle  of  dominant  control.  Each  brings  out  the 
factors  of  greatest  importance  in  the  distribution  of  the  people  in  a  given  region. 
Furthermore,  the  facts  are  compressed  within  the  limits  of  a  small  rectangle.  This  com- 
pression, though  great,  respects  all  essential  relations.  For  example,  every  location  on 
these  diagrams  has  a  concrete  illustration  but  the  accidental  relations  of  the  field  have 
been  omitted;  the  essential  relations  are  preserved.  Each  diagram  is,  therefore,  a 
kind  of  generalized  type  map.  It  bears  somewhat  the  same  relation  to  the  facts  of 
human  geography  that  a  block  diagram  does  to  physiography.  The  darkest  shading 
represents  steep  snow-covered  country;  the  next  lower  grade  represents  rough  but 
snow-free  country;  the  lightest  shading  represents  moderate  relief;  unshaded  parts 
represent  plain  or  plateau.  Small  circles  represent  forest  or  woodland;  small  open- 
spaced  dots,  grassland.  Fine  alluvium  is  represented  by  small  closely  spaced  dots; 
coarse  alluvium  by  large  closely  spaced  dots. 

To  take  an  illustration.  In  Figure  32  we  have  the  Apurimac  region  near  Pasaje 
(see  location  map.  Fig.  20).  At  the  lower  edge  of  the  rectangle  is  a  snow-capped 
outlier  of  the  Cordillera  Vilcapampa.  The  belt  of  rugged  country  represents  the 
lofty,  steep,  exposed,  and  largely  inaccessible  ridges  at  the  mid-elevations  of  the 
mountains  below  the  glaciated  slopes  at  the  heads  of  tributary  valleys.  The  villages 
in  the  belt  of  pasture  might  well  be  Incahuasi  and  Corralpata.  The  floors  of  the 
large  canyons  on  either  hand  are  bordered  by  extensive  alluvial  fans.  The  river 
courses  are  sketched  in  a  diagrammatic  way  only,  but  a  map  would  not  be  different 
in  its  general  disposition.  Each  location  is  justified  by  a  real  place  with  the  same 
essential  features  and  relations.  In  making  the  change  there  has  been  no  alteration 
of  the  general  relation  of  the  alluvial  lands  to  each  other  or  to  the  highland.  By 
suppressing  unnecessary  details  there  is  produced  a  diagram  whose  essentials  have 
simple  and  clear  relations.  When  such  a  regional  diagram  is  amplified  by 
photographs  of  real  conditions  it  becomes  a  sort  of  generalized  picture  of  a 
large  group  of  geographic  facts.  One  could  very  well  extend  the  method  to  the 
whole  of  South  America.  It  would  be  a  real  service  to  geography  to  draw  up  a  set 
of,  say,  twelve  to  fifteen  regional  diagrams,  still  further  generalized,  for  the  whole 
of  the  continent.  As  a  broad  classification  they  would  serve  both  the  specialist  and 
the  general  student.  As  the  basis  for  a  regional  map  of  South  America  (hey  would 
be  invaluable  if  worked  out  in  sufficient  detail  and  constructed  on  the  indispensable 
basis  of  field  studies. 


52  .  THE  ANDES  OF  SOUTHERN  PERU 

time  of  peace  are  probably  iu  large  part  responsible  for  the  pres- 
ent widespread  occupation  of  the  Peruvian  mountains. 

The  loftiest  habitation  in  the  world  (Fig.  24)  is  in  Peru.  Be- 
tween Antabamba  and  Cotahuasi  occur  the  highest  passes  in  the 
Maritime  Cordillera.  We  crossed  at  17,400  feet  (5,300  m.),  and 
three  hundred  feet  lower  is  the  last  outpost  of  the  Indian  shep- 
herds. The  snowline,  very  steeply  canted  away  from  the  sun,  is 
between  17,200  and  17,600  feet  (5,240  to  5,360  m.).  At  frequent 
intervals  during  the  three  months  of  winter,  snow-falls  during  the 
night  and  terrific  hailstorms  in  the  late  afternoon  drive  both  shep- 
herds and  flocks  to  the  shelter  of  leeward  slopes  or  steep  canyon 
walls.  At  our  six  camps,  between  16,000  and  17,200  feet  (4,876 
and  5,240  m.),  in  September,  1911,  the  minimum  temperature 
ranged  from  4°  to  20°  F.  The  thatched  stone  hut  that  we  passed 
at  17,100  feet  and  that  enjoys  the  distinction  of  being  the  highest 
in  the  world  was  in  other  respects  the  same  as  the  thousands  of 
others  in  the  same  region.  It  sheltered  a  family  of  five.  As  we 
passed,  three  rosy-cheeked  children  almost  as  fat  as  the  sheep 
about  them  were  sitting  on  the  ground  in  a  corner  of  the  corral 
playing  with  balls  of  wool.  Hundreds  of  alpacas  and  sheep 
grazed  on  the  hill  slopes  and  valley  floor,  and  their  tracks  showed 
plainly  that  they  were  frequently  driven  up  to  the  snowline  in 
those  valleys  where  a  trickle  of  water  supported  a  band  of  pasture. 
Less  than  a  hundred  feet  below  them  were  other  huts  and  flocks. 

Hf-re  we  have  the  limits  of  altitude  and  the  limits  of  resources. 
The  intervalley  spaces  do  not  support  grass.  Some  of  them  are 
quite  bare,  others  are  covered  with  mosses.  It  is  too  high  for  even 
tlic  tola  bush — that  pioneer  of  Alpine  vegetation  in  the  Andes. 
The  distance'  to  Cotahuasi  is  75  miles  (120  km.),  to  Aiif;ib;niil)a 
r)()  miles  (80  km.).  Tlionce  wool  must  be  ship])o(l  l)y  ])n('k-<rain 
1o  the  r.'lilrond  in  jlic  one  case  250  miles  (400  km.)  lo  Ar('(iiii});i,  in 
tlic  otiicr  case  200  miles  (320  km.)  to  Cuzco.  Kvvn  the  potatoes 
and  b;irl('y,  wliich  must  Ik-  imported,  come  from  valleys  several 
<i;iys'  journey  awny.  The  question  naturally  arises  why  these  peo- 
ple live  on  the  rim  of  the  world.     Did  they  seek  out  these  neglected 

•  Distances  are  not  taken  from  the  map  but  from  the  trnil. 


THE  COUNTRY  OF  THE  SHEPHERDS  53 

pastures,  or  were  they  driven  to  them!  Do  they  live  here  by 
choice  or  of  necessity!  The  answer  to  these  questions  introduces 
two  other  geographic  factors  of  prime  importance,  the  one  phys- 
ical, the  other  economic.  ^ 
i  The  main  tracts  of  lofty  pasture  above  Antabamba  cover  moun- 
tain slopes  and  valley  floor  alike,  but  the  moist  valley  floors  supply 
the  best  grazing.  Moreover,  the  main  valleys  have  been  inten- 
sively glaciated.  Hence,  though  their  sides  are  steep  walls,  their 
floors  are  broad  and  flat.  Marshy  tracts,  periodically  flooded,  are 
scattered  throughout,  and  here  and  there  are  overdeepened  por- 
tions where  lakes  have  gathered.  There  is  a  thick  carpet  of  grass, 
also  numerous  huts  and  corrals,  and  many  flocks.  At  the  upii)er 
edge  of  the  main  zone  of  pasture  the  grasses  become  thin  and  with 
increasing  altitude  give  out  altogether  except  along  the  mplst  val- 
ley floors  or  on  shoulders  where  there  is  seepage. 

If  the  streams  head  in  dry  mountain  slopes  without  snow  the 
grassy  bands  of  the  valley  floor  terminate  at  moderate  elevations. 
If  the  streams  have  their  sources  in  snowfields  or  glaciers  there  is 
a  more  uniform  run-off,  and  a  ribbon  of  pasture  may  extend  to  the 
snowline.  To  the  latter  class  belong  the  pastures  that  support 
these  remote  people. 

In  the  case  of  the  Maritime  Andes  the  great  elevation  of  the 
snowline  is  also  a  factor.  If,  in  Figure  25,  we  think  of  the  snow- 
line as  at  the  upper  level  of  the  main  zone  of  pasture  then  we 
should  have  the  conditions  shown  in  Figure  36,  where  the  limit  of 
general,  not  local,  occupation  is  the  snowline,  as  in  the  Cordillera 
Vilcapampa  and  between  Chuquibambilla  and  Antabamba. 

A  third  factor  is  the  character  of  the  soil.  Large  amounts  of 
volcanic  ash  and  lapilli  were  thrown  out  in  the  late  stages  of  vol- 
canic eruption  in  which  the  present  cones  of  the  Maritime  Andes 
were  formed.  The  coarse  texture  of  these  deposits  allows  the 
ready  escape  of  rainwater.  The  combination  of  extreme  aridity 
and  great  elevation  results  in  a  double  restraint  upon  vegetation. 
Outside  of  the  moist  valley  floors,  with  their  film  of  ground 
moraine  on  whose  surface  plants  find  a  more  congenial  soil,  there 
is  an  extremely  small  amount  of  pasture.  |  Here  are  the  natural 


/ 


54  THE  ANDES  OF  SOUTHERN  PERU 

grazing  grounds  of  the  tieet  vicuna.  They  occur  in  hundreds,  and 
so  remote  and  little  disturbed  are  they  that  near  the  main  pass 
one  may  count  them  by  the  score.  As  we  rode  by,  many  of  them 
only  stared  at  us  without  taking  the  trouble  to  get  beyond  rifle 
shot.  It  is  not  difficult  to  believe  that  the  Indians  easily  shoot 
great  numbers  in  remote  valleys  that  have  not  been  hunted  for 
years. 

!  The  extreme  conditions  of  life  existing  on  these  lofty  plateaus 
are  well  shoAVTi  by  the  readiness  with  which  even  the  hardy  shep- 
herds avail  themselves  of  shelter.  Wherever  deep  valleys  bring  a 
milder  climate  within  reach  of  the  pastures  the  latter  are  unpopu- 
lated for  miles  on  either  side.  The  sixty-mile  stretch  between 
Chuquibamba  and  Salamanca  is  without  even  a  single  hut,  though 
there  are  pastures  superior  to  the  ones  occupied  by  those  loftiest 
huts  of  all.  Likewise  there  are  no  permanent  homes  between  Sala- 
manca and  Cotahuasi,  though  the  shepherds  migrate  across  the 
belt  in  the  milder  season  of  rain.  Eastward  and  northward  to- 
ward the  crest  of  the  Maritime  Cordillera  there  are  no  huts 
within  a  day's  journey  of  the  Cotahuasi  canyon.  Then  there  is  a 
group  of  a  dozen  just  under  the  crest  of  the  secondary  range  that 
parallels  the  main  chain  of  volcanoes.  Thence  northward  there 
are  a  number  of  scattered  huts  between  15,500  and  1(5,500  feet 
(4,700  and  5,000  m.),  until  we  reach  the  highest  habitations  of  all 
at  17,100  feet  (5,210  m.). 

The  unpopulated  belts  of  lava  plateau  bordering  the  entrenched 
valleys  are,  however,  as  distinctly  ''sustenance"  spaces,  to  use 
Penck's  term,  as  the  irrigated  and  fertile  alluvial  fans  in  the  bot- 
tom of  the  valley.  This  is  well  shown  when  the  rains  come  and 
flocks  of  llamas  and  sheep  are  driven  forth  from  the  valleys  to  the^ 
best  pastures.  It  is  equally  well  shown  by  the  distribution'^of  the 
shepherds'  homes.  These  are  not  down  on  the  wiinii  cauyoii  lloor, 
separated  by  a  h;ilf  d.-iy's  journey  from  Die  grazing.  ^J'hey  are  in 
the  intrenchefl  trihntary  valleys  of  Figure  2(1  or  just  within  the 
jjiii  (.f  the  canyon.  It  is  not  shelter  from  the  cold  buf  from  the 
wind  that  chiefly  determines  their  location.  They  are  also  kept 
near  the  rim  of  the  canyon  by  the  pressure  of  thq  farming  popu- 


THE  COUNTRY  OF  THE  SHEPHERDS 


55 


lation  from  below.  Every  hundred  feet  of  descent  from  the  arid 
plateau  (Fig.  29)  increases  the  water  supply.  Springs  increase 
in  number  and  size;  likewise  belts  of  seepage  make  their  appear- 
ance. The  gradients  in  many  places  diminish,  and  flattish  spurs 
and  shoulders  interrupt  the  generally  steep  descents  of  the  canyon 


^ 


J  p  R I G  AT  E  D  ■■  W<?iJ  ■'^''/i^/'fn' 


■:>N^\lMl"M"' 


■       SMALLTRICKL£  OR  SPRING  ■^•a, 

ENDING  ON  SURFACE  OF  PLATEAU      '*■' 


Fig.  26 — Regional  diagram  to  show  tlie  pliysical  relations  in  the  lava  plateau  of 
the  Maritime  Cordillera  west  of  the  continental  divide.  For  location,  see  Fig.  20. 
Trails  lead  up  the  intrenched  tributaries.  If  the  irrigated  bench  (lower  right  corner) 
is  large,  a  town  will  be  located  on  it.  Shepherds'  huts  are  scattered  about  the  edge 
of  the  girdle  of  spurs.  There  is  also  a  string  of  huts  in  the  deep  sheltered  head  of 
each  tributarj'.     See  also  Fig.  29  for  conditions  on  the  valley  or  canyon  floor. 


wall.  Every  change  of  this  sort  has  a  real  value  to  the  farmer  and 
means  an  enhanced  price  beyond  the  ability  of  the  poor  shepherd 
to  pay.  If  you  ask  a  wealthy  hacendado  on  the  valley  floor  (Fig. 
29),  who  it  is  that  live  in  the  huts  above  him,  he  will  invariably  say 
"los  Indios,"  with  a  shrug  meant  to  convey  the  idea  of  poverty 
and  worthlessness.  Sometimes  it  is  ''los  Indios  pobres,"  or 
merely  "los  pobres."     Thus  there  is  a  vertical  stratification  of 


56  THE  ANDES  OF  SOUTHERN  PERU 

society  corresponding  to  the  superimposed  strata  of  climate  and 
land. 

At  Salamanca  (Fig.  62)  I  saw  this  admirably  displayed  under 
circumstances  of  unusual  interest.  The  floor  and  slopes  of  the 
valley  are  more  completely  terraced  than  in  any  other  valley  I 
know  of.  In  the  photograph,  Fig.  30,  which  shows  at  least  2,500 
feet  of  descent  near  the  town,  one  cannot  find  a  single  patch  of  sur- 
face that  is  not  under  cultivation.  The  valley  is  simply  filled  with 
people  to  the  limit  of  its  capacity.  Practically  all  are  Indians,  but 
with  many  grades  of  wealth  and  importance.  When  we  rode  out 
of  the  valley  before  daybreak,  one  September  morning  in  1911, 
there  was  a  dead  calm,  and  each  step  upward  carried  us  into  a 
colder  stratum  of  air.  At  sunrise  we  had  reached  a  point  about 
2,000  feet  above  the  town,  or  14,500  feet  (4,420  m.)  above  sea  level. 
We  stood  on  the  frost  line.  On  the  opposite  wall  of  the  valley  the 
line  was  as  clearly  marked  out  as  if  it  had  been  an  irrigating  canal. 
The  light  was  so  fully  reflected  from  the  millions  of  frost  crystals 
above  it  that  both  the  mountainside  and  the  valley  slopes  were 
sparkling  like  a  ruffled  lake  at  sunrise.  Below  the  frost  line  the 
slopes  were  dark  or  covered  with  yellow  barley  and  wheat  stubble 
or  green  alfalfa. 

/  It  happened  that  the  frost  line  was  near  the  line  of  division 
'between  corn  and  potato  cultivation  and  also  near  the  line  separat- 
ing the  steep  rough  upper  lands  from  the  cultivable  lower  lands. 
Xot  a  liabitation  was  in  sight  above  us,  except  a  few  scattered 
miserable  huts  near  broken  terraces,  gullied  by  wet-weather 
streams  and  grown  up  to  weeds  and  brush.  Below  us  were  well- 
fultivated  fields,  and  the  stock  was  kept  in  bounds  by  stone  fences 
and  corrals;  above,  the  half-wild  burros  and  mules  roamed  about 
everywhere,  and  only  the  sheep  and  llamas  were  in  rude  enclo- 
Hurcs.  Tims  in  :i  Imll'  lioiii-  we  ])ass(M]  llic  fi-oiilici'  Ix'lwccn  tlie 
agriciilf iir;il  I'nlk  hdow  (lie  frost  line  :m(l  llic  sli(>i)li('i-(l  folk  above 
it. 

Ill  M  ff'W  spots  the  line  followed  an  irregular  course,  as  where 
(latter  lands  were  developed  at  unusual  elevations  or  where  air 
drainage  altered  the  normal  temperature.     And  at  one  place  the 


Fifl.   27. 


Fig.   28. 


Fig.  27 — Terraced  valley  slopes  at  Huaynacotas,  Cotahuasi  Valley,  Peru.  Eleva- 
tion  11,500   feet    (3,500  ra.). 

Fig.  28 — The  highly  cultivated  and  thoroughly  terraced  floor  of  the  Ollantaytambo 
Valley  at  Ollantaytambo.     This  is  a  tributary  of  the  Urubamba;  elevation,  11,000  feet. 


FlO.  29 — C'otaliuaMi  on  llir  lloor  of  tin-  ('(itjilmasi  <!iiiynii.  'I'hc  even  sUvliiic  of  the 
background  \h  on  u  riitlicr  cvcntopiM-d  lava  plateau.  I  lie  Icnacc  on  tlic  left  of  the 
town  JM  forrni-d  on  linicMtonc,  which  is  overlain  l>y  lava  Howh.  A  lliick  dcpuNit  of  ter- 
raced alhiviuni  may  he  wvu  on  the  valley  lloor,  and  it  \h  on  inu:  of  the  lower  terraces 
that  the  city  of  CotaliuaMi  htands.  The  higher  Urraccs  are  in  iriany  caserf  too  dry  for 
cultivation.  The  canyon  in  nearly  7,(><t()  fe<'t  ('i.l.'U)  in.)  deej)  and  has  been  en)  tiirongii 
one   hundred   principal    lava   (Iowh. 


THE  COUNTRY  OF  THE  SHEPHERDS        57 

frost  actually  stood  on  the  young  corn,  which  led  us  to  speculate 
on  the  possibility  of  securing  from  Salamanca  a  variety  of  maize 
that  is  more  nearly  resistant  to  light  frosts  than  any  now  grown 
in  the  United  States.  In  the  endless  and  largely  unconscious  ex- 
perimentation of  these  folk  perched  on  the  valley  walls  a  result 
may  have  been  achieved  ahead  of  that  yet  reached  by  our  pro- 
fessional experimenters.  Certain  it  is  that  nowhere  else  in  the 
world  has  the  potato  been  grown  under  such  severe  climatic  con- 
ditions as  in  its  native  land  of  Peru  and  Bolivia.  The  hardiest 
varieties  lack  many  qualities  that  we  'prize.  They  are  small  and 
bitter.  But  at  least  they  will  grow  where  all  except  very  few 
cultivated  plants  fail,  and  they  are  edible.  Could  they  not  be  im- 
ported into  Canada  to  push  still  farther  northward  the  limits  of 
cultivation?  Potatoes  are  now  grown  at  Forts  Good  Hope  and 
McPherson  in  the  lower  Mackenzie  basin.  Would  not  the  hardiest 
Peruvian  varieties  grow  at  least  as  far  north  as  the  continental 
timber  line!  I  believe  they  could  be  grown  still  farther  north. 
They  will  endure  repeated  frosts.  They  need  scarcely  any  cultiva- 
tion. Prepared  in  the  Peruvian  manner,  as  cliuno,  they  could  be 
kept  all  winter.  Being  light,  the  meal  derived  from  them  could 
be  easily  packed  by  hunters  and  prospectors.  An  Indian  will  carry 
in  a  pouch  enough  to  last  him  a  week.  Why  not  use  it  north  of 
the  continental  limit  of  other  cultivated  plants  since  it  is  the 
pioneer  above  the  frost  line  on  the  Peruvian  mountains  ? 

The  relation  between  farmer  and  shepherd  or  herdsman  grows 
more  complex  where  deeper  valleys  interrupt  the  highlands  and 
mountains.  The  accompanying  sketch,  Fig.  32,  represents  typical 
relations,  though  based  chiefly  on  the  Apurimac  canyon  and  its 
surroundings  near  Pasaje.  First  there  is  the  snow-clad  region  at 
the  top  of  the  country.  Below  it  are  grassy  slopes,  the  homes  of 
mountain  shepherds,  or  rugged  mountain  country  unsuited  for 
grazing.  Still  lower  there  is  woodland,  in  patches  chiefly,  but  with 
a  few  large  continuous  tracts.  The  shady  sides  of  the  ravines  and 
the  mountains  have  the  most  moisture,  hence  bear  the  densest 
growths.  Finally,  the  high  country  terminates  in  a  second  belt 
of  pasture  below  the  woodland. 


58 


THE  ANDES  OF  SOUTHERN  PERU 


Whenever  streams  descend  from  the  snow  or  woodland  coun- 
try there  is  water  for  the  stock  above  and  for  irrigation  on  the 
alhivial  fan  below.    But  the  spur  ends  dropping  off  abruptly  sev- 


Fi«.  .'12 — Regional  (liagram  representing  tlie  dit'ii  paiiyoncd  country  west  of  the 
K:iht<'rn  (rjrdillcra  in  tlie  region  of  the  Ai»iriuiaf.  For  pliotograph  sec  Fig.  94.  For 
flirt  Ikt  <|im(  ription  Her  noU-  on  ngional  (liafiramH.  ]>.  51.  NumberH  1,  2,  and  3  corre- 
Hpond  in  piiHitioii  in  the  h.ihh-  miinlMTrt  in   I'ig.  .'?•'{. 


era]  tlionsand  fe(!t  have  a  limited  area  and  no  nnmiiig  streams, 
and  tlie  ground  water  is  liundreds  of  feet  down.  'I'licre  is  grass 
for  stock,  but  tliore  is  no  water.    In  some  places  the  stock  is  driven 


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THE  COUNTRY  OF  THE  SHEPHERDS  59 

back  and  forth  every  few  days.  In  a  few  places  water  is  brought 
to  the  stock  by  canal  from  the  woodland  streams  above,  as  at 
Corralpata.^  In  the  same  way  a  canal  brings  water  to  Pasaje 
hacienda  from  a  woodland  strip  many  miles  to  the  west.  The 
little  canal  in  the  figure  is  almost  a  toy  construction  a  few  inches 

VALLEY    ZONE  MOUNTAIN     ZONE 


Fig.   33 — Valley  climates  of  the  canyoned  region  shown  in  Fig.   32. 

wide  and  deep  and  conveying  only  a  trickle  of  water.  Yet  on  it 
depends  the  settlement  at  the  spur  end,  and  if  it  were  cut  the  peo- 
ple would  have  to  repair  it  immediately  or  establish  new  homes. 
The  canal  and  the  pasture  are  possible  because  the  slopes  are 
moderate.  They  were  formed  in  an  earlier  cycle  of  erosion  when 
the  land  was  lower.  They  are  hung  midway  between  the  rough 
mountain  slopes  above  and  the  steep  canyon  walls  below  (Fig.  32). 
Their  smooth  descents  and  gentle  profiles  are  in  very  pleasing 
contrast  to  the  rugged  scenery  about  them.  The  trails  follow  them 
easily.  Where  the  slopes  are  flattest,  farmers  have  settled  and 
produce  good  crops  of  corn,  vegetables,  and  barley.  Some  farm- 
ers have  even  developed  three-  and  four-story  farms.  On  an  al- 
luvial fan  in  the  main  valley  they  raise  sugar  cane  and  tropical 
and  subtropical  fruits ;  on  the  flat  upper  slopes  they  produce  corn ; 
in  the  moister  soil  near  the  edge  of  the  woodland  are  fields  of 
mountain  potatoes;  and  the  upper  pastures  maintain  flocks   of 


=■  Compare  with  Raimondi's  description  of  Quiches  on  the  left  bank  of  the  Marafion 
at  an  elevation  of  9,885  feet  (3,013  m.)  :  "the  few  small  springs  scarcely  suffice  for 
the  little  patches  of  alfalfa  and  other  sowings  have  to  depend  on  the  precarious 
rains.  .  .  .  Every  drop  of  water  is  carefully  guarded  and  from  each  spring  a  series 
•of  well-like  basins  descending  in  staircase  fashion  make  the  most  of  tlie  scant  supply." 
(El  Departamento  de  Ancachs,  Lima,  1873.) 


60  THE  ANDES  OF  SOUTHERN  PERU 

I  sheep.    In  one  district  this  change  takes  place  in  a  distance  that 
'  may  be  covered  in  five  hours.    Generally  it  is  at  least  a  full  and 
hard  day's  journey  from  one  end  of  the  series  to  the  other. 

Wherever  these  features  are  closely  associated  they  tend  to  be 
controlled  by  the  planter  in  some  deep  valley  thereabouts.  Where 
they  are  widely  scattered  the  people  are  independent,  small 
groups  living  in  places  nearly  inaccessible.  Legally  they  are  all 
under  the  control  of  the  owners  of  princely  tracts  that  take  in  the 
whole  country,  but  the  remote  groups  are  left  almost  wholly  to 
themselves.  In  most  cases  they  are  supposed  to  sell  their  few 
connnercial  products  to  the  Uacendado  who  nominally  owns  their 
land,  but  the  administration  of  this  arrangement  is  left  largely  to 
chance.  The  shepherds  and  small  farmers  near  the  plantation  are 
more  dependent  upon  the  planter  for  supplies,  and  also  their 
wants  are  more  varied  and  numerous.  Hence  they  pay  for  their 
better  location  in  free  labor  and  in  produce  sold  at  a  discount. 

So  deep  are  some  of  the  main  canyons,  like  the  Apurimac  and 
the  Cotahuasi,  that  their  floors  are  arid  or  semi-arid.  The  fortunes 
of  Pasaje  are  tied  to  a  narrow  canal  from  the  moist  woodland  and 
a  tiny  brook  from  a  hollow  in  the  valley  wall.  Where  the  water 
has  thus  been  brought  down  to  the  arable  soil  of  the  fans  there  are 
rich  plantations  and  farms.  Elsewhere,  however,  the  floor  is  quite 
dry  and  uncultivated.  In  small  spots  here  and  there  is  a  little 
seepage,  or  a  few  springs,  or  a  mere  thread  of  water  that  will  not 
support  a  plantation,  wlierefore  there  have  come  into  existence 
the  valley  herdsmen  and  shepherds.  Their  intimate  knowledge  of 
the  moist  places  is  their  capital,  quite  as  much  as  are  the  cattle  and 
sheep  thoy  own.  In  a  sense  their  lands  are  the  neglected  crumbs 
from  the  rich  man's  table.  So  we  find  the  shepherd  from  the  hills 
invading  the  valleys  just  as  the  valley  farmer  has  invaded  lli<' 
country  of  llie  slieytlierd. 

Tlie  basin  1y})e  of  topography  enlls  into  existence  a  set  of  rela- 
tions quite  distinct  from  citlier  of  those  we  have  just   desei-ibed. 
V       Figure  :U  represents  tlie  main  facts.     Tlie  rieli  and  eomi)arat ively 
flat  floor  of  the  l)asin  sn[)poi-ts  most  (d"  th<'  pcoph-.     'Phc  alhivial 
fans  tributary  thereto  are  composed  of  fine  material  on  their  outer 


THE  COUNTRY  OF  THE  SHEPHERDS 


61 


Fig.  34 — Regional  diagram  to  show  the  typical  physical  conditions  and  relations 
in  an  intermont  basin  in  the  Peruvian  Andes.  The  Cuzco  basin  (see  Fig.  37)  is  an 
actual  illustration;  it  should,  however,  be  emphasized  that  the  diagram  is  not  a 
"  map "  of  that  basin,  for  whilst  conditions  there  have  been  utilized  as  a  basis,  the 
generalization  has  been  extended  to  illustrate  many  basins. 


margin  and  of  coarse  stony  waste  at  their  heads.  Hence  the  val- 
ley farms  also  extend  over  the  edges  of  the  fans,  while  only  pas- 
ture or  dense  chaparral  occupies  the  upper  portions.     Finally 


62 


THE  ANDES  OF  SOUTHERN  PERU 


there  is  the  steep  margin  of  the  basin  where  the  broad  and  moder- 
ate slopes  of  the  highland  break  do"«Ti  to  the  floor  of  the  basin. 

If  a  given  basin  lies  at  an  elevation  exceeding  14,000  feet 
(4,270  m.),  there  will  be  no  cultivation,  only  pasture.  If  at  10,000 
or  11,000  feet  (3,000  or  3,350  m.),  there  will  be  grain  fields  below 


ZONE  Of  STORtD  PRECIPITATION 

SOURCES  OF  BASIN  STREAMS 


ZONE   OF    CULTIVATION 

f-LIMIT  OF  IRRIGATION  AND—; 
I     INTENSIVE    CULTIVATION 


ZONE  OF  MOUNTAIN    PASTURF«i 


ORANGE  AND  BANANA      6000' 


P^O.  35 — Climatic  cross-section  showing  the  location  of  various  zones  of  cultivation 
and  pasture  in  a  typical  intermont  basin  in  the  Peruvian  Andes.  The  thickness  of 
the  dark  symbols  on  the  right  is  proportional  to  the  amount  of  each  staple  that  is 
produced  at  the  corresponding  elevation.     See  also  the  regional  diagram   Fig.  34. 


and  potato  fields  above  (Figs.  34  and  35).  If  still  lower,  fruit  will 
come  in  and  finally  sugar  cane  and  many  other  subtropical  prod- 
ucts, as  at  Abancay.  Much  will  also  depend  upon  the  amount  of 
available  water  and  the  extent  of  the  pasture  land.  Thus  the 
densely  populated  Cuzco  basin  has  a  vast  mountain  territory 
tributary  to  it  and  is  itself  within  the  limits  of  barley  and  wheat 
cultivation.  Furthermore  there  are  a  number  of  smaller  basins,  like 
the  Anta  basin  on  tlio  north,  which  are  dependent  upon  its  better 
markets  and  transportation  facilities.  A  dominance  of  this  kind 
is  self-stimulating  and  at  last  is  out  of  all  proportion  to  the 
origin.'il  differences  of  nature.  Cuzco  has  also  profited  as  the  gate- 
way to  tiic  great  northeastern  v.-illoy  region  of  the  Urubamba  and 
its  big  tributaries.  All  of  llie  vniied  products  of  the  subtropical 
\alleys  lind  tlidr  iinniedinle  market  at  Ciizco. 

Tlie  effect  of  this  natural  conspiracy  of  conditions  has  l)een  to 
place  the  liistoric  city  of  Cuzco  in  a  position  of  extraordinary  im- 
portanee.  Hundreds  of  years  be^re  the  Spanish  Conquest  it  was 
a  center  of  far-reaching  influence,  the  home  of  the  powerful  Inca 
kings.    From  it  the  strong  arm  of  authority  and  conquest  was  ex- 


THE  COUNTRY  OF  THE  SHEPHERDS  63 

tended;  to  it  came  tribute  of  grain,  wool,  and  gold.    To  one  ac- 
customed to  look  at  such  great  consequences  as  having  at  least 
some  ultimate  connection  with  the  earth,  the  situation  of  Cuzco 
would  be  expected  to  have  some  unique  features.    With  the  glori- 
ous past  of  that  city  in  mind,  no  one  can  climb  to  the  surround- 
ing heights  and  look  down  upon  the  fertile  mountain- rimmed  plain 
as  at  an  ordinary  sight  (Fig.  37).    The  secret  of  those  great  con^ 
quests  lies  not  only  in  mind  but  in  matter.    If  the  rise  of  the  Incas  \  q 
to  power  was  not  related  to  the  topography  and  climate  of  the    I 
Cuzco  basin,  at  least  it  is  certain  that  without  so  broad  and  noble  , 
a  stage  the  scenes  would  have  been  enacted  on  a  far  differeni/ 
scale. 

The  first  Inca  king  and  the  Spanish  after  the  Incas  found  here 
no  mobile  nomadic  tribes  melting  away  at  the  first  touch,  no 
savages  hiding  in  forest  fastnesses,  but  a  well-rooted  agricultural 
race  in  whose  center  a  large  city  had  grown  up.    Without  a  city  \' 
and  a  fertile  tributary  plain  no  strong  system  of  government  could 
be  maintained  or  could  even  arise.    It  is  a  great  advantage  in  rul-   1 
ing  to  have  subjects  that  cannot  move.    The  agricultural  Indians  / 
of  the  Andean  valleys  and  basins,  in  contrast  to  the  mobile  shep- 
herd, are  as  fixed  as  the  soil  from  which  they  draw  their  life. 

The  full  occupation  of  the  pasture  lands  about  the  Cuzco  basin 
is  in  direct  relation  to  the  advantages  we  have  already  enumer- 
ated.   Every  part  of  the  region  feels  the  pressure  of  population.  \ 
Nowhere  else  in  the  Peruvian  Andes  are  the  limits  between  cultiva-    \ 
tion  and  grazing  more  definitely  drawn  than  here.     Moreover, 
there  is  today  a  marked  difference  between  the  types  that  inhabit 
highland  and  basin.    The  basin  Indian  is  either  a  debauched  city     . 
dweller  or,  as  generally,  a  relatively  alert  farmer.    The  shepherds    ' 
are  exceedingly  ignorant  and  live  for  the  most  part  in  a  manner 
almost  as  primitive  as  at  the  time  of  the  Conquest.    They  are  shy   ( 
and  suspicious.    Many  of  them  prefer  a  life  of  isolation  and  rarely 
go  doAvn  to  the  town.     They  live  on  the  fringe  of  culture.     The  i. 
new  elements  of  their  life  have  come  to  them  solely  by  accident 
and  by  what  might  be  called  a  process  of  ethnic  seepage.     The 
slight  advances  that  have  been  made  do  not  happen  by  design,  they 


64  THE  ANDES  OF  SOUTHERN  PERU 

merely  happen.    Put  the  highland  shepherd  in  the  basin  and  he 
I    would  starve  in  competition  with  the  basin  type.    Undoubtedly  he 
j    would  live  in  the  basin  if  he  could.     He  has  not  been  driven  out 
\of  the  basin;  he  is  kept  out. 

And  thus  it  is  around  the  border  of  the  Abancay  basin  and 
others  like  it.  Only,  the  Abancay  basin  is  lower  and  more  varied 
as  to  resources.  The  Indian  is  here  in  competition  with  the  capi- 
talistic white  planter.  He  lives  on  the  land  by  sufferance  alone. 
Farther  up  the  slopes  are  the  farms  of  the  Indians  and  above 
^hem  are  the  pastures  of  the  ignorant  shepherds.  Whereas  the 
/jlndian  farmer  who  raises  potatoes  clings  chiefly  to  the  edge  of 
/  xhe  Cuzco  basin  where  lie  the  most  undesirable  agricultural  lands, 
the  Indian  farmers  of  Abancay  live  on  broad  rolling  slopes  like 
those  near  the  pass  northward  toward  Huancarama.  They  are 
unusually  prosperous,  with  fields  so  well  cultivated  and  fenced, 
so  clean  and  productive,  that  they  remind  one  somewhat  of  the 
beautiful  rolling  prairies  of  Iowa. 

It  remains  to  consider  the  special  topographic  features  of  the 
mountain  environments  we  are  discussing,  in  the  Vilcapampa 
region  on  the  eastern  border  of  the  Andes  (Fig.  36).  The  Cordil- 
lera Vilcapampa  is  snow-crested,  containing  a  number  of  fine 
white  peaks  like  Salcantay,  Soray,  and  Soiroccocha  (Fig.  140). 
There  are  many  small  glaciers  and  a  few  that  are  several 
miles  long.  There  was  here  in  glacial  times  a  much  larger  system 
of  glaciers,  wliicli  lived  long  enough  to  work  grcvit  changes  in  the 
topography.  'I'lic  floors  of  the  glaciated  valleys  were  smoothed 
and  broadened  and  their  gradients  flattened  (Figs.  137  and  190). 
TIh'  side  walls  wen;  stecpciKMl  ;ni<l  pi'ceipitous  cirques  were 
formf'd  .'it  the  xallcy  heads.  Also,  llicre  were  built  across  the  val- 
leys a  iiuiiihcr  of  stony  morainic  ridges.  With  all  these  changes 
there  was,  however,  bill  liKlc  ('(Tcel  upon  the  main  masses  of  the 
biir  int('i-\;ill('V  s|)iirs.  ^Tlicy  i'<'iii;iiii  ;is  Ix'l'orc  bold,  wind-swept, 
l)r<)K'''ii,  and  iicnily  inaccessible. 

The  work  of  the  glaciers  aids  the  mountain  ])eople.  The  stony 
moraines  afford  tlieiTi  Inindy  sizable  bnilding  material  for  their 
stone  huts  and  their  numerous  corrals.     The  thick  tufts  of  i^rass 


THE  COUNTRY  OF  THE  SHEPHERDS 


65 


Fig.  36 — Regional  diagram  for  the  Eastern  Cordillera  or  Cordillera  Vilcapampa. 
Note  the  crowded  zones  on  the  right  (east  and  north)  in  contrast  to  the  open  suc- 
cession on  the  left.  In  sheltered  places  woodland  extends  even  higher  than  shown. 
At  several  points  patches  of  it  grow  right  under  the  snowline.  Other  patches  grow 
on   the  floors  of   the  glaciated  valley  troughs. 

in  the  marshy  spots  in  the  overdeepened  parts  of  the  valleys  fur- 
nish them  with  grass  for  their  thatched  roofs.     And,  most  im- 


66  THE  ANDES  OF  SOUTHERN  PERU 

portant  of  all,  the  flat  valley  floors  have  the  best  pasture  in  the 
whole  mountain  region.  There  is  plenty  of  water.  There  is  seclu- 
sion, and,  if  a  fence  be  built  from  one  valley  wall  to  another  as  can 
be  done  with  little  labor,  an  entire  section  of  the  valley  may  be 
inclosed.  A  village  like  Choquetira,  located  on  a  bench  on  the  val- 
ley side,  commands  an  extensive  view  up  and  down  the  valley — an 
important  feature  in  a  grazing  village  where  the  corrals  cannot 
always  be  built  near  the  houses  of  the  owners.  Long,  finger-like 
belts  of  highland-shepherd  population  have  thus  been  extended 
into  the  mountain  valleys.  Sheep  and  llamas  drift  right  up  to 
the  snowline. 

There  is,  however,  a  marked  difference  between  the  people  on 
opposite  sides  of  the  Cordillera  Vilcapampa.  On  the  west  the  moun- 
tains are  bordered  by  a  broad  highland  devoted  to  grazing.  On 
the  east  there  is  a  narrower  grazing  belt  leading  abruptly  down 
to  tropical  valleys.  The  eastern  or  leew^ard  side  is  also  the 
warmer  and  wetter  side  of  the  Cordillera.  The  snowline  is  sev- 
eral hundred  feet  lower  on  the  east.  The  result  is  that  patches  of 
scrub  and  even  a  little  w^oodland  occur  almost  at  the  snowline  in 
favored  places.  Mist  and  storms  are  more  frequent.  The  grass 
is  longer  and  fresher.  Vegetation  in  general  is  more  abundant. 
The  people  make  less  of  wool  than  of  cattle,  horses,  and  mules. 
Vilcabamba  pueblo  is  famous  for  its  horses,  wiry,  long-haired  lit- 
tle beasts,  as  hardy  as  Shetland  ponies.  We  found  cattle  grazing 
only  five  hundred  feet  below  the  limit  of  perpetual  snow.  There 
are  cultivated  spots  only  a  little  farther  down,  and  only  a  thou- 
sand feet  below  the  snow  are  abandoned  terraces.  At  the  same 
elevation  are  twisted  quenigo  trees,  at  least  two  hundred  years 
old,  as  shown  by  their  rings  of  growth.  Thus  the  limits  of  agricul- 
turo  are  higher  on  the  east;  likewise  the  limits  of  cattle  grazing- 
tliat  Tialurally  goes  with  agriculture.  Sheep  would  thrive,  but 
llamas  do  bcllci-  In  drici-  coiinli-y,  and  llic  slicplicrd  must  needs 
mix  liis  flocks,  for  llic  wool  wliich  is  his  chief  product  requires 
transportaliou  and  only  the  cheap  and  acclimated  llama  is  at  the 
shepherd's  disposnl.  From  those  facts  it  will  be  seen  that  the 
anthropo-geographic  contrasts  between  the  east<'r7i  ;md  western 


Fig.   37. 


Fig.   3S. 


Fig.  37 — Cuzco  and  a  portion  of  the  famous  Cuzco  basin  with  bordering  grassy 
highlands. 

Fig.  38 — Terraced  valley  slopes  and  floor,  Urubamba  Valley  between  Urubaniba 
and  Ollantavtambo. 


Fio.   39. 


y'-n^^ 


''tc;l(«^'' 


<*^  K^*^'         .^  a^  4k  •>  *■' 


I'lC.     1(1. 

Fl(j.  .'J9 — lluifliihiiii,  iicnr  ('liii(iiiil);iiiil»illii,  :i  lypiciil  nioiiiitaiii  village,  in  the 
vnllovH  of  tlic  Ccntrnl    Hiinj^cH,    I'mivian    Aiuk'H. 

Fio.  40 — Potato  field  iil)ovc  \ilc!ilmiiiJ)a  at  12,000  ft-ct  (.{.(iOO  in.).  Tlio  natural 
Bod  in  hrokfii  by  a  Htccl-Mliod  utick  :iiiil  tin-  Hcod  potato  dropped  into  a  men!  puncture. 
It  rccciveH   no   attcritinn    tlicnaftir   until    liaiMst    lime. 


THE  COUNTRY  OF  THE  SHEPHERDS  6T 

sides  of  the  Cordillera  Vilcapampa  are  as  definite  as  the  climatic 
and  vegetal  contrasts.  This  is  especially  well  shown  in  the  differ- 
ences between  dry  Arma,  deep-sunk  in  a  glaciated  valley  west  of 
the  crest  of  the  mountains,  and  wet  Puquiura,  a  half-day's  journey 
east  of  the  crest.  There  is  no  group  on  the  east  at  all  comparable 
to  the  shepherds  of  Choquetira,  either  in  the  matter  of  thorough- 
going dependence  upon  grazing  or  in  that  of  dependence  upon 
glacial  topography. 

Topography  is  not  always  so  intimately  related  to  the  life  of 
the  people  as  here.  In  our  own  country  the  distribution  of  avail- 
able water  is  a  far  greater  factor.  The  Peruvian  Andes  therefore 
occupy  a  distinctive  place  in  geography,  since,  more  nearly  than 
in  most  mountains,  their  physical  conditions  have  typical  human 
relations  that  enable  one  clearly  to  distinguish  the  limits  of  con- 
trol of  each  feature  of  climate  or  relief. 


CHAPTER  VI 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES 


On  the  northeastern  border  of  the  Peruvian  Andes  long  moun- 
tain spurs  trail  down  from  the  regions  of  snow  to  the  forested 
plains  of  the  Amazon.     Here  are  the  greatest  contrasts  in  the 

physical  and  human  geog- 
raphy of  the  Andean  Cordil- 
lera. So  striking  is  the  fact 
that  every  serious  student 
of  Peru  finds  himself  com- 
pelled to  cross  and  recross 
this  natural  frontier.  The 
thread  of  an  investigation 
runs  irregularly  now  into 
one  border  zone,  now  into 
another.  Out  of  the  forest 
came  the  fierce  marauders 
who  in  the  early  period 
drove  back  the  Inca  pioneers. 
Down  into  the  forest  to 
escape  from  the  Spaniards 
fled  the  last  Inca  niul  his 
fugitive  court.  Here  the 
Jesuit  fathers  sowed  their 
missions  along  the  forest  margin,  and  watched  ovci-  them  for 
twf)  hundred  years.  From  tlie  mountain  border  one  rubber 
projcet  jifter  jinotlicr  lias  ])een  hiunched  into  the  vast  swampy 
lowlands  llii'cadcd  hy  great  rivers.  As  an  elJmic  Ixumdary 
the  eastern  mountain  Ixu-der  of  iN'i'u  and  l^)oli\ia  has  no  e(iual 
elsewhere  in  Soiilli  Ainei-iea.  P'roni  the  earliest  antiquity  ihe 
tribes  of  th(!  grass-covered  mountains  ;nid  the  hordes  of  the  for- 
ested plains  have  had  strongly  divergent  customs  and  speech,  that 
])red  enduring  hatred  and  led  to  fi-efjuent  and  bloody  strife. 

OH 


Fio.  41 — Regional  diagram  of  the  eastern 
aspfct  of  the  Cordillera  Vilcapainpa.  See  also 
Fip.  17  of  wliich  this  is  an  enlarged  section. 


lit;.  42 — Rug  weaver  at  Cotalniasi.  The  industry  is  limited  to  a  small  group  of 
related  families,  living  in  the  Cotahuasi  Canyon  near  Cotahuasi.  Tlie  rugs  are  made 
of  alpaca  wool.  Pure  black,  pure  white,  and  various  shadi's  of  mixed  gray  wool  are 
employed.  The  result  is  that  tlie  rugs  have  "fast"'  colors  that  always  retain  their 
original  contrasts.  They  are  made  only  to  order  at  the  homes  of  the  purchasers.  The 
money  payment  is  small,  but  to  it  is  added  board  and  lodging,  besides  tobacco,  liqueurs, 
and  wine.  Before  drinking  tlicy  dip  their  finger-tips  in  the  wine  and  sprinkle  the 
earth  "that  it  may  be  fruitful,"  the  air  "that  it  may  be  warm,"  the  rug  "that  it  may 
turn  out  well,"  and  finally  themselves,  making  the  sign  of  the  cross.  Then  they  set 
to  work. 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        69 

On  the  steepest  spurs  of  the  Pampaconas  Valley  the  traveler 
may  go  from  snow  to  pasture  in  a  half  day  and  from  pasture  to 
forest  in  the  same  time.  Another  day  he  is  in  the  hot  zone  of  the 
larger  valley  floors,  the  home  of  the  Machigangas.  The  steep 
descents  bring  out  the  superimposed  zones  with  diagrammatic 
simplicity.  The  timber  line  is  as  sharply  marked  as  the  edge  of  a 
cultivated  field.  At  a  point  just  beyond  the  huts  of  Pampaconas 
one  may  stand  on  a  grassy  spur  that  leads  directly  up — a  day's 
journey — to  the  white  summits  of  the  Cordillera  Vilcapampa. 
Yet  so  near  him  is  the  edge  of  the  forest  that  he  is  tempted  to 
try  to  throw  a  stone  into  it.  In  an  hour  a  bitter  wind  from  the 
mountains  may  drive  him  to  shelter  or  a  cold  fog  come  rolling  up 
from  the  moist  region  below.  It  is  hard  to  believe  that  oppressive 
heat  is  felt  in  the  valley  just  beneath  him. 

In  the  larger  valleys  the  geographic  contrasts  are  less  sharp 
and  the  transition  from  mountains  to  plain,  though  less  spectacu- 
lar, is  much  more  complex  and  scientifically  interesting.  The  for- 
est types  interfinger  along  the  shady  and  the  sunny  slopes.  The 
climate  is  so  varied  that  the  forest  takes  on  a  diversified  character 
that  makes  it  far  more  useful  to  man.  The  forest  Indians  and 
the  valley  planters  are  in  closer  association.  There  are  many 
islands  and  peninsulas  of  plateau  population  on  the  valley  floor. 
Here  the  zones  of  climate  and  the  belts  of  fertile  soil  have  larger 
areas  and  the  land  therefore  has  greater  economic  value.  Much 
as  the  valley  people  need  easier  and  cheaper  communication  with 
the  rest  of  Peru  it  is  no  exaggeration  to  say  that  the  valley  prod- 
ucts are  needed  far  more  by  the  coast  and  plateau  peoples  to 
make  the  republic  self-supporting.  Coca,  wood,  sugar,  fruit,  are 
in  such  demand  that  their  laborious  •  and  costly  transportation 
from  the  valleys  to  the  plateau  is  now  carried  on  with  at  least 
some  profit  to  the  valley  people.  Improved  transportation  would 
promote  travel  and  friendship  and  supply  a  basis  for  greater 
political  unity. 

A  change  in  these  conditions  is  imminent.  Years  ago  the 
Peruvian  government  decreed  the  construction  of  a  railway  from 
€uzco  to  Santa  Ana  and  preliminary  surveys  were  made  but  with- 


70  THE  ANDES  OF  SOUTHERN  PERU 

out  any  immediate  practical  effect.  By  June,  1914,  12.4  miles  (20 
km.)  had  been  opened  to  traffic.  The  total  length  of  the  proposed 
line  is  112  miles  (180  km.),  the  gauge  is  to  be  only  2.46  feet 
(75  cm.),'  and  the  proposed  cost  several  millions  of  dollars.  The 
financial  problem  may  be  solved  either  by  a  diversion  of  local 
revenues,  derived  from  taxes  on  coca  and  alcohol,  or  by  borrowed 
foreign  capital  guaranteed  by  local  revenues. 

A  shrubby  vegetation  is  scattered  along  the  valley  from  the 
village  of  Urubamba,  12,000  feet  (3,658  m.)  above  sea  level,  to  the 
Canyon  of  Torontoy.    It  is  local  and  of  little  value.    Trees  appear 
at  Ollantaytambo,  11,000  feet  (3,353  m.),  and  here  too  are  more 
extensive  wheat  and  maize  fields  besides  throngs   of  cacti  and 
great  patches   of  wild  geraniums.     On   our   valley  journey   we 
camped  in  pleasant  fields  flanked  by  steep  hills  whose  summits 
each  morning  were  tipped  with  snow.     Enormous  alluvial  fans 
have  partly  filled  up  the  valleys  and  furnished  broad  tracts  of 
fertile  soil.    The  patient  farmers  have  cleared  away  the  stones  on 
the  flatter  portions  and  built  retaining  walls  for  the  smooth  fields 
required  for  irrigation.    In  places  the  lower  valley  slopes  are  ter- 
raced in  the  most  regular  manner  (Fig.  38).    Some  of  the  fans  are 
too  steep  and  stony  for  cultivation,  exposing  bare  tracts  which 
wash  down  and  cover  the  fields.    Here  and  there  are  stone  walls 
built  especially  to  retain  the  rush  of  mud  and  stones  that  the  rains 
bring    down.      ^Many    of    them    were    overthrown    or    completely 
])nri((l.     Unless  the  stream  channels   on   1ho  fans  are  carefully 
watcliod  and  effective  works  kept  up,  the  labor  of  years  may  be 
destroyed  in  a  single  slide  from  the  head  of  a  steep  fan. 
/     Each  group  of  fans  has  a  population  proportioned  to  its  size 
/and  fertility.     If  there  are  broad  expanses  a  town  like  Urubamba 
or  a  groat  hacienda   like   Ilu;i(l(|uirin   is  siu-c  io  Ix'   round.     One 
grou))  of  liugc  stony  fans  lu'hiw  Urul»;mil);i    (l^'ig.  ISO)   lias  only 
a  tliin  iiopnliition,  for  tlic  soil  is  coarse  and  infertile  and  \ho  rivers 
deeply   inlreneln'd.      In   some   ]il;iees   tlie   tiny    fans  perched  high 
upon  the  flanks  of  tlie  mountains  wher(i  little  tributaries  burst  out 

'Daily  Cnm.  and   Trndc  INjioii,  .Iiiiic    10,    101  t.  No.    K!').   nnd   foininorcc  Kojiorta, 
Marrli  20,  191G,  No.  60. 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        71 

of  steep  ravines  are  cultivated  by  distant  owners  who  also  till 
parts  of  the  larger  fans  on  the  main  valley  floors.  Between  the 
fans  of  the  valley  bottoms  and  the  smooth  slopes  of  the  high 
plateaus  are  the  unoccupied  lands — the  steep  canyon  walls.  Only 
in  the  most  highly  favored  places  where  a  small  bench  or  a  patch 
of  alluvium  occurs  may  one  find  even  an  isolated  dwelling.  The 
stair-like  trails,  in  some  places  cut  in  solid  rock,  zigzag  up  the 
rocky  slopes.  An  ascent  of  a  thousand  feet  requires  about  an 
hour's  travel  with  fresh  beasts.  The  valley  people  are  therefore 
"walled  in.  If  they  travel  it  is  surely  not  for  pleasure.  Even  busi- 
ness trips  are  reduced  to  the  smallest  number.  The  prosperity 
and  happiness  of  the  valley  people  are  as  well  known  among  the 
plateau  people  as  is  their  remarkable  bread.  Their  climate  has  a 
combination  of  winter  rain  and  winter  cold  with  light  frosts  that 
is  as  favorable  for  good  wheat  as  the  continuous  winter  cold  and 
snow  cover  of  our  northern  Middle  West.  The  colder  grainfields 
of  the  plateau  are  sowed  to  barley  chiefly,  though  there  is  also 
produced  some  wheat.  Urubamba  wheat  and  bread  are  exported 
in  relatively  large  quantities,  and  the  market  demands  greater 
quantities  than  the  valley  can  supply.  Oregon  and  Washington 
flour  are  imported  at  Cuzco,  two  days'  muleback  journey  from  the 
wheat  fields  of  Urubamba. 

Such  are  the  conditions  in  the  upper  Urubamba  Valley.  The 
lower  valley,  beginning  at  Huadquiiia,  is  8,000  feet  (2,440  m.) 
above  sea  level  and  extends  down  to  the  two-thousand-foot  con- 
tour at  Rosalina  and  to  one  thousand  feet  (305  m.)  at  Pongo  de 
Mainique.  The  upper  and  lower  sections  are  only  a  score  of  miles 
(30  km.)  apart  between  Huadquiiia  and  Torontoy,  but  there  is  a 
difference  in  elevation  of  three  thousand  feet  (915  m.)  at  just  the 
level  where  the  maximum  contrasts  are  produced.  The  cold  tim- 
ber line  is  at  10,500  feet  (3,200  m.).-    Winter  frosts  arc  common 


^  Reference  to  the  figrtires  in  this  chapter  will  show  great  variation  in  the  level 
of  the  timber  line  depending  upon  insolation  as  controlled  by  slope  exposure  and 
upon  moisture  directly  as  controlled  largely  by  exposure  to  winds.  In  some  places 
these  controls  counteract  each  other;  in  other  places  they  promote  each  other's 
effects.  The  topographic  and  climatic  cross-sections  and  regional  diagrams  else- 
where in  this  book  also  emphasize  the  patchiness  of  much  of  the  woodland  and  scrub, 
some  noteworthy  examples  occurring  in   the   chapter  on   the  Eastern   Andes.     Two  of 


72  THE  ANDES  OF  SOUTHERN  PERU 

at  the  one  place;  they  are  absent  altogether  at  the  other.  Toroutoy 
produces  corn;  Huadquiua  produces  sugar  cane. 

These  contrasts  are  still  further  emphasized  by  the  sharp  topo- 
graphic break  between  the  two  unlike  portions  of  the  valley.  A 
few  miles  below  Torontoy  the  Urubamba  plunges  into  a  mile-deep 
granite  canyon.  The  walls  are  so  close  together  that  it  is  impos- 
sible from  the  canyon  floor  to  get  into  one  photograph  the  highest 
and  steepest  walls.  At  one  place  there  is  over  a  mile  of  descent 
in  a  horizontal  distance  of  2,000  feet.  Huge  granite  slabs  fall  off 
along  joint  planes  inclined  but  15°  from  the  vertical.  The  effect 
is  stupendous.  The  canyon  floor  is  littered  with  coarse  waste  and 
the  gradient  of  the  river  greatly  steepened.  There  is  no  cultiva- 
tion. The  trees  cling  with  difficulty  to  patches  of  rock  waste  or 
to  the  less-inclined  slopes.  There  is  a  thin  crevice  vegetation  that 
outlines  the  joint  pattern  where  seepage  supplies  the  venturesome 
roots  with  moisture.  Man  has  no  foothold  here,  save  at  the  top 
of  the  country,  as  at  Machu  Picchu,  a  typical  fortress  location 
safeguarded  by  the  virtually  inaccessible  canyon  wall  and  con- 
nected with  the  main  ridge  slopes  only  by  an  easily  guarded 
narrow  spur.  Toward  the  lower  end  of  the  canyon  a  little 
finer  alluvium  appears  and  settlement  begins.  Finally,  after 
a  tumble  of  three  thousand  feet  over  countless  rapids  the  river 
emerges  at  Colpani,  where  an  enormous  mass  of  alluvium  has 
been  dumped.  The  well-intrenched  river  has  already  cut  a 
larif  pari  of  it  away.  A  little  farther  on  is  Huadquifia  in 
tlie  Salcantay  Valley,  whore  a  tributary  of  the  Urubamba  has 
built  up  a  sheet  of  alluvial  land,  bright  green  with  cane.  From 
the  distant  peaks  of  Salcantay  and  its  neighbors  well-fed  streams 
descend  to  fill  the  irrigation  channels.  '^Phus  the  snow  and  rock- 
waste  ol"  tlic  (lislaiil  TiioiintaiTis  ai'c  turned  into  corn  and  sugar  on 
tlu'  valley  lowlands. 

the  mo»t  rfmnrkablo  cnHP»  nre  the  patch  of  woodlniifl  at  14,500  feet  (4.420  m.)  just 
undfr  thf  lianjfinj?  plnrior  of  Soirncoofhn  niul  tin-  othor  tho  qucniRo  Hcnil)  on  the 
Inva  plnfraii  above  riiiif|iiihnmha  at  13.000  fcot  (H.OrtO  m.).  The  Rtrong  coniprossion 
of  rlimntin  zonen  in  tho  T*nil)ainha  Valley  l)elow  Santa  Ana  hrinR«  into  sharp  contrast 
tlie  pr.THBy  ridge  wlopes  facing  the  snn  aiKl  (lie  foresferl  sldpes  that  have  a  high  propor- 
tion of  nharle.  Fig.  !i4  reprcHintu  the  gi-nerjil  distribution  but  tho  details  are  far 
moro  complicated.     Sec  also  Figs.  5.3A  and  5.3n.      (Sec  Coropuna  Q\iadraiigle. ) 


■■^*l^^ 


.  —  — ••—:»?; 


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I'U,.    4. 


Fig.  44 — The  snow-capped  Cordillera  \'ilcapampa  north  of  Yueay  and  the  upper 
canyon  of  the  Urubamba  from  the  wheat  fields  near  Chinchero.  In  the  foreground 
is  one  of  the  well-graded  mature  slopes  of  Fig.  123.  The  crests  of  the  mountains  lie 
along  the  axis  of  a  granite  intrusion.  The  extent  of  the  snowfields  is  extraordinary 
in  view  of  the  low  latitude,   13°   S. 

Fig.  45 — Rounded  slopes  due  to  glacial  action  at  Panipaconas  in  the  Pampaconas 
Valley  near  Vilcabamba.  A  heavy  tropical  forest  extends  up  the  Pampaconas  \'alley 
to  the  hill  slopes  in  the  background.  Its  upper  limit  of  growth  is  about  10,000  feet 
(3,050   m.).     The   camera   is   pointed   slightly  downhill. 


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THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        73 

The  Cordillera  Vilcapampa  is  a  climatic  as  well  as  a  topo- 
graphic barrier.  The  southwestern  aspect  is  dry;  the  northeast- 
ern aspect  forested.  The  gap  of  the  canyon,  it  should  be  noticed, 
comes  at  a  critical  level,  for  it  falls  just  above  the  upper  border 
of  the  zone  of  maximum  precipitation.  The  result  is  that  though 
mists  are  driven  through  the  canyon  by  prolonged  up-valley 
winds,  they  scatter  on  reaching  the  plateau  or  gather  high  up  on 
the  flanks  of  the  valley  or  around  the  snowy  peaks  overlooking 
the  trail  between  Ollantaytambo  and  Urubamba.  The  canyon 
walls  are  drenched  with  rains  and  even  some  of  the  lofty  spurs 
are  clothed  with  dense  forest  or  scrub. 

Farther  down  the  valley  winds  about  irregularly,  now  pushed 
to  one  side  by  a  huge  alluvial  fan,  now  turned  by  some  resistant- 
spur  of  rock.  Between  the  front  range  of  the  Andes  and  the 
Cordillera  Vilcapampa  there  is  a  broad  stretch  of  mountain  coun- 
try in  the  lee  of  the  front  range  which  rises  to  7,000  feet  (2,134  m.) 
at  Abra  Tocate  (Fig.  15),  and  falls  off  to  low  hills  about  Rosalina. 
It  is  all  very  rough  in  that  there  are  nowhere  any  flats  except  for 
the  narrow  playa  strips  along  the  streams.  The  dense  forest  adds 
to  the  difficulty  of  movement.  In  general  appearance  it  is  very 
much  like  the  rugged  Cascade  country  of  Oregon  except  that  the 
Peruvian  forest  is  much  more  patchy  and  its  trees  are  in  many 
places  loaded  with  dense  dripping  moss  which  gives  the  landscape 
a  somber  touch  quite  absent  from  most  of  the  forests  of  ihe 
temperate  zone.  ^ 

The  fertility  of  the  eastern  valleys  of  Peru — the  result  of  a 
union  of  favorable  climate  and  alluvial  soil — has  drawn  the 
planter  into  this  remote  section  of  the  country,  but  how  can  he  dis- 
pose of  his  products!  Even  today  with  a  railway  to  Cuzco  from 
the  coast  it  is  almost  impossible  for  him  to  get  his  sugar  and  cacao 
to  the  outside  world.^  How  did  he  manage  before  even  this  rail- 
way was  built?  How  could  the  eastern  valley  planter  live  before 
there  were  any  railways  at  all  in  Peru?  In  part  he  has  solved 
the  problem  as  the  moonshiner  of  Kentucky  tried  to  solve  it,  and    i 

•  Commenting   on   the  excelli  nee   of   the   cacao   of   the   montaua    of   the   Urubamba    \J 
von  Tschudi  remarked   (op.  cit.,  p.  37)   that  the  long  land  transport  prevented  its  usii 
in  Lima  where  the  product  on  the  market  is  that  imported  from  Guayaquil. 


74.  THE  ANDES  OF  SOUTHERN  PERU 

from  cane  juice  makes  aguardiente  (brandy).  The  latter  is  a 
much  more  valuable  product  than  sugar,  hence  (1)  it  will  bear  a 
higher  rate  of  transportation,  or  (2)  it  will  at  the  same  rate  of 
transportation  yield  a  greater  net  profit.  In  a  remote  valley 
where  sugar  could  not  be  exported  on  account  of  high  freight 
rates  brandy  could  still  be  profitably  exported. 

The  same  may  be  said  for  coca  and  cacao.  They  are  condensed 
and  valuable  products.  Both  require  more  labor  than  sugar  but 
are  lighter  in  bulk  and  thus  have  to  bear,  in  proportion  to  their 
value,  a  smaller  share  of  the  cost  of  transportation.  At  the  end 
of  three  years  coca  produces  over  a  ton  of  leaves  per  acre  per 
year,  and  it  can  be  made  to  produce  as  much  as  two  tons  to  the 
acre.  The  leaves  are  jDicked  four  times  a  year.  They  are  worth 
from  eight  to  twelve  cents  gold  a  pound  at  the  plantation  or  six- 
teen cents  a  pound  at  Cuzco.  An  orchard  of  well-cultivated  and 
irrigated  cacao  trees  Avill  do  even  better.  Once  they  begin  to  bear 
the  trees  require  relatively  little  care  except  in  keeping  out  weeds 
and  brush  and  maintaining  the  water  ditches.  However,  the  pods 
must  be  gathered  at  just  the  right  time,  the  seeds  must  be  raked 
and  dried  with  expert  care,  and  after  that  comes  the  arduous 
labor  of  the  grinding.  This  is  done  by  hand  on  an  inclined  i^lane 
with  a  heavy  round  stone  whose  corners  fit  the  hand.  The  choco- 
late must  then  be  worked  into  cakes  and  dried,  or  it  must  be 
sacked  in  heavy  cowhide  and  sowed  so  as  to  be  practically  air 
tiglit.  AVlion  eight  or  ten  years  old  the  trees  are  mature  and  each 
may  then  bear  a  thousand  pounds  of  seed. 

Tf  hibor  were  cheap  and  abundant  the  whole  trend  of  tropical 
agriculture  in  the  eastern  Valleys  would  be  toward  intensive  culti- 
vation and  the  production  of  expensive  exports.  But  labor  is  ac- 
tually scarce.  Every  ])laiit('r  must  have  agents  who  cnn  send  men 
down  from  tlic  ])lat('au  towns.  And  tlio  j^lantcr  himself  must  use 
his  labor  to  flif  best  advantage.  Aguardiente  requires  less  labor 
than  cacao  and  coca.  The  cane  costs  about  as  much  in  labor  the 
first  year  as  the  coca  bush  or  the  cacao  tree,  but  after  that  much 
less.  Tlio  mnnufacturo  of  brandy  from  tlie  cane  juice  requires  lit- 
tlf   labor   though   much   expensive   macliiucry.      For  chocolate,   a 


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THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        75 

storehouse,  a  grinding  stone,  and  a  rake  are  all  that  are  required. 
So  the  planter  must  work  out  his  own  salvation  individually.  He 
must  take  account  of  the  return  upon  investments  in  machinery, 
of  the  number  of  hands  he  can  command  from  among  the  ' '  f aena ' ' 
or  free  Indians,  of  the  cost  and  number  of  imported  hands  from 
the  valley  and  plateau  towns,  and,  finally,  of  the  transportation 
rates  dependent  upon  the  number  of  mules  in  the  neighborhood, 
and  distance  from  the  market.  If  in  addition  the  labor  is  skilfully 
employed  so  as  to  have  the  tasks  which  the  various  products  re- 
quire fall  at  different  periods  of  the  year,  then  the  planter  may 
expect  to  make  money  upon  his  time  and  get  a  return  upon  his 
initial  investment  in  the  land.* 

The  type  of  tropical  agriculture  which  we  have  outlined  is 
profitable  for  the  few  planters  who  make  up  the  white  population 
of  the  valleys,  but  it  has  a  deplorable  effect  upon  the  Indian  popu- 
lation. Though  the  planters,  one  and  all,  complain  bitterly  of  the 
drunken  habits  of  their  laborers,  they  themselves  put  into  the 
hands  of  the  Indians  the  means  of  debauchery.  Practically  thej 
whole  production  of  the  eastern  valleys  is  consumed  in  Peru. 
What  the  valleys  do  not  take  is  sent  to  the  plateau,  where  it  is  the 
chief  cause  of  vicious  conduct.  Two-thirds  of  the  prisoners  in  the 
city  jails  are  drunl^ards,  and,  to  be  quite  plain,  they  are  virtually 
supplied  with  brandy  by  the  planter,  who  could  not  otherwise 
make  enough  money.  So  although  the  planter  wants  more  and 
better  labor  he  is  destroying  the  quality  of  the  little  there  is,  and, 
if  not  actually  reducing  the  quantity  of  it,  he  is  at  least  very  cer- 
tainly reducing  the  rate  of  increase. 

The  difficulties  of  the  valley  planter  could  be  at  least  partly 
overcome  in  several  ways.  The  raihvay  will  reduce  transporta- 
tion costs,  especially  when  the  playas  of  the  valleys  are  all 
cleared  and  the  exports  increased.    Moreover  the  eastern  valleys 

*  The  inadequacy  of  the  labor  supply  was  a  serious  obstacle  in  the  early  days 
as  well  as  now.  In  the  documents  pertaining  to  the  "  Obispados  y  Audiencia  del 
Cuzco"  (Vol.  11,  p.  349  of  the  "  Juicio  dc  Lfmites  entre  el  Perfl  y  Bolivia,  Prueba 
Peruana  presentada  al  Gobierno  de  la  Ropfiblica  Argentina  por  Victor  ^1.  Maurtua," 
Barcelona,  1906)  we  find  the  report  that  the  natives  of  the  curacy  of  Ollantaytambo 
who  came  down  frona  the  hills  to  Huadquina  to  hear  mass  were  detained  and  compelled 
to  give  a  day's  service  on  the  valley  plantations  under  pain  of  chastisement. 


76  THE  ANDES  OF  SOUTHERN  PERU 

are  capable  of  producing  things  of  greater  utility  than  brandy 
and  coca  leaves.    So  far  as  profits  are  increased  by  cheaper  trans- 
portation we  may  expect  the  planter  to  produce  more  rather  than 
less  of  brandy  and  coca,  his  two  most  profitable  exports,  unless 
other  products  can  be  found  that  are  still  more  profitable.    The 
ratio  of  profits  on  sugar  and  brandy  will  still  be  the  same  unless 
the  government  increases  the  tax  on  brandy  until  it  becomes  no 
more  profitable  than  sugar.     That  is  what  ought  to  be  done  for 
the  good  of  the  Indian  population.    It  cannot  be  done  safely  with- 
out offering  in  its  place  the  boon  of  cheaper  railway  transporta- 
tion for  the  sugar  crop.     Furthermore,  with  railway  improve- 
ments should  go  the  blessings  that  agricultural  experiments  can 
bestow.    A  government  farm  in  a  suitable  place  would  establish 
rice  and  cotton  cultivation.    Many  of  the  playas  or  lower  alluvial 
lands  along  the  rivers  can  be  irrigated.    Only  a  small  fraction  of 
the  water  of  the  Rio  Urubamba  is  now  turned  out  upon  the  fields. 
For  a  large  part  of  the  year  the  natural  rainfall  would  suffice  to 
keep  rice  in  good  condition.    Six  tons  a  year  are  now  grown  on 
Hacienda  Sahuayaco  for  local  use  on  account  of  the  heavy  rate 
on  rice  imported  on  muleback  from  Cuzco,  whither  it  comes  by 
sea  and  by  trail  from  distant  coastal  valleys.    The  lowland  people 
also  need  rice  and  it  could  be  sent  to  them  down  river  by  an  easier 
route  than  that  over  which  their  supplies  now  come.    It  should  be 
exported  to  the  highlands,  not  imported  therefrom.    There  are  so 
many  varieties  adapted  to  so  many  kinds  of  soil  and  climate  that 
large  amounts  should  be  produced  at  fair  profits. 

The  cotton  plant,  on  the  other  hand,  is  more  particular  about 
climate  and  especially  the  duration  of  dry  and  wet  seasons;  in 
spite  of  this  its  requirements  are  all  met  in  the  Santa  Ana  Valley. 
Thf  rniiifjill  is  modoratc  niid  llicro  is  an  abundance  of  di-y  warm 
soil.  TIk-  i)laii1  f'(.iil(l  mako  most  of  ils  iri-owlli  in  llic  wot  season, 
and  111''  four  moiillis  of  cooler  dry  season  with  only  occasional 
showers  would  favor  bolli  a  bright  staple  and  a  good  picking  sea- 
son. More  labor  would  be  I'eqnired  Cor  col  I  on  and  rice  and  for 
the  increased  production  of  cacao  than  nndei-  the  present  system. 
This  would  not   be  a   real  diniculty  if  the  existing  labor  supply 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        77 

were  conserved  by  the  practical  abolition,  through  heavy  taxation, 
of  the  brandy  that  is  the  chief  cause  of  the  laborer's  vicious  habits. 
This  is  the  first  step  in  securing  the  best  return  upon  the  capital 
invested  in  a  railway.  Economic  progress  is  here  bound  up  with 
a  very  practical  morality.  Colonization  in  the  eastern  valleys,  of 
which  there  have  been  but  a  few  dismal  attempts,  will  only  extend 
the  field  of  influence,  it  will  not  solve  the  real  problem  of  bringing 
the  people  of  the  rich  eastern  territory  of  Peru  into  full  and 
honorable  possession  of  their  natural  wealth.  . 

The  value  of  the  eastern  valleys  was  kno\vii  in  Inca  times,  for 
their  stone-faced  terraces  and  coca-drying  patios  may  still  be  seen 
at  Echarati  and  on  the  border  of  the  Chaupimayu  Valley  at 
Sahuayaco.  Tradition  has  it  that  here  were  the  imperial  coca 
lands,  that  such  of  the  forest  Indians  as  were  enslaved  were 
obliged  to  work  upon  them,  and  that  the  leaves  were  sent  to  Cuzco 
over  a  paved  road  now  covered  with  "montafia"  or  forest.  The- 
Indians  still  relate  that  at  times  a  mysterious,  wavering,  white 
light  appears  on  the  terraces  and  hills  where  old  treasure  lies 
buried.  Some  of  the  Indians  have  gold  and  silver  objects  which 
they  say  were  dug  from  the  floors  of  hill  caves.  There  appears  to 
have  been  an  early  occupation  of  the  best  lands  by  the  Spaniards, 
for  the  long  extensions  down  them  of  Quechua  population  upon 
which  the  conquerors  could  depend  no  doubt  combined  with  the 
special  products  of  the  valley  to  draw  white  colonists  thither.'^ 

•  The  Spanish  occupation  of  the  eastern  valleys  was  early  and  extensive.  Im- 
mediately after, the  capture  of  the  young  Inca  Tupac  Amaru  and  the  final  subjugation 
of  the  province  of  Vilcapampa  colonists  started  the  cultivation  of  coca  and  cane. 
Development  of  the  main  Urubamba  Valley  and  tributary  valleys  proceeded  at  a  good 
rate:  so  also  did  their  troubles.  Baltasar  de  Ocampo  writing  in  1610  (Account  of  the 
Province  of  Vilcapampa,  Hakluyt  Soc.  Pubis.,  Ser.  2,  Vol.  22.  1907,  pp.  203-247)  relates 
the  occurrence  of  a  general  uprising  of  the  negroes  employed  on  the  sugar  plantations 
of  the  region.  But  the  peace  and  prosperity  of  every  place  on  the  eastern  frontier  was 
unstable  and  quite  generally  the  later  eighteenth  and  earlier  nineteenth  centuries  saw 
a  retreat  of  the  border  of  civilization.  The  native  rebellion  of  the  mid-eightoenth 
century  in  the  montana  of  Chanchamayo  caused  entire  abandonment  of  a  previously 
flourishing  area.  When  Eaimondi  wrote  in  1885  (La  Montana  de  Chanchamayo,  Lima, 
1885)  some  of  the  ancient  hacienda  sites  were  still  occupied  by  savages.  In  the 
Paucartambo  valleys,  settlement  began  by  the  end  of  the  sixteenth  century  and  at  the 
beginning  of  the  nineteenth  before  their  complete  desolation  by  the  savages  they  were 
highly  prosperous.  Paucartambo  town,  itself,  once  important  for  its  commerce  in  coca 
is  now   in   a   sadly  decadent  condition. 


78  THE  ANDES  OF  SOUTHERN  PERU 

General  Miller,''  writing  in  1836,  mentions  the  villages  of  Incbarate 
(Ecliarati)  and  Sant'  Ana  (Santa  Ana)  but  discourages  the 
idea  of  colonization  "...  since  tbe  river  .  .  .  bas  lofty  moun- 
tains on  eitber  side  of  it,  and  is  not  navigable  even  for  boats." 

In  tbe  ''Itinerario  de  los  viajes  de  Eaimondi  en  el  Peru"  '  tbere 
is  an  interesting  account  of  tbe  settlement  by  tbe  Rueda  family 
of  tbe  great  estate  still  beld  by  a  Rueda,  tbe  wife  of  Sefior  Duque. 
Jose  Rueda,  in  1829,  was  a  government  deputy  representative  and 
took  bis  pay  in  land,  acquiring  valuable  territory  on  wbicb  tbere 
was  notbing  more  tban  a  mission.  In  1830  Rueda  ceded  certain 
lands  in  "arriendo"  (rent)  and  on  tbese  were  founded  tbe  baci- 
endas  Pucamoco,  Sabuayaco,  etc. 

Senor  Gonzales,  tbe  present  owner  of  Hacienda  Sabuayaco,  re- 
cently obtained  bis  land — a  princely  estate,  ten  miles  by  forty — 
for  12,000  soles  ($6,000).  In  a  few  years  be  bas  cleared  tbe  best 
tract,  built  several  miles  of  canals,  bewed  out  bouses  and  furni- 
ture, planted  coca,  cacao,  cane,  coffee,  rice,  pepper,  and  cotton, 
and  would  not  sell  for  $50,000.  Moreover,  instead  of  being  a 
superintendent  on  a  neigbboring  estate  and  keeping  a  shop 
in  Cuzco,  wbere  bis  large  family  was  a  source  of  great  ex- 
pense, be  bas  become  a  wealthy  landowner.  He  bas  educated  a 
son  in  tbe  United  States.  He  is  importing  machinery,  such  as  a 
rice  thresher  and  a  distilling  plant.  His  son  is  looking  forward 
to  tlic  i)iii('hase  of  still  more  playa  land  down  river.  He  pays  a 
sol  a  day  to  each  laborer,  securing  men  from  Cotabambas  and 
Al)ancay,  wbere  there  are  many  Indians,  a  low  standard  of  wages, 
little  unoccupied  land,  and  a  hot  climate,  so  that  the  immigrants 
do  not  need  to  become  accliuiatized. 

The  deepest  valb-ys  in  I  lie  l'];istei-ii  Andes  of  Peru  have  a 
semi  ;iri<i  crmuite  wliicb  l>i-iiigs  in  its  ti'.-iiii  ;i  \nri(>ty  of  unusual 
geogr.-ipliic  i-cl.'itioiis.  Al  (irst  as  one  (Icsceiids  llie  \'nlley  the 
kIkkIv    :i)|(I    sunny    slopes    siiow    sli;ii-ply    contrasted    vegetation. 


•  Notiro  of  a  Jfnirnoy  to  Um!  Norlliward  and  nlwo  to  the  Eastward  of  Cnzcn.  and 
amoiif?  th«'  Cliunclios  Indians,  in  J\ily,  IH.'J.').  Joiirn.  l^)yal  ficog.  Soc,  \'<il.  fi,  1830, 
pp.  174- ISO. 

'  Hoi.  Soc.  (Joog.  dc  Mini.,  \'.)1.  8,  1898,  p.  45. 


Fig.  51. 


Fig. 


Fig.  51 — Robledo's  mountain-side  trail  in  the  Urubamba  Valley  below  Rosalina. 

Fig.  52 — An  epiphyte  partly  supported  by  a  dead  host  at  Ro-alina,  elevation  2.000 
feet.  The  epiphyte  bears  a  striking  resemblance  to  a  horned  beast  whose  arched  back, 
tightly  clasped  fingers,  and  small  eyes  give  it  a  peculiarly  malignant  and  life-like 
expression. 


Fig.  53A, 


IH,. 


I'Ki.  O.'JA— 'Jlir  Minootli  ^^riiHMV  slupcs  at  tlic  jimclinn  ,,f  ih,.  'ijiiiat  ili  (left)  and 
Iriilmniba   (ri^'lit)    riviTH  in'ur  J'hIh'IIoii. 

Kio.  5:{U — iJiMtiihiitioii  (»f  vo^ctation  in  tlic  I  riibaniha  \  allry  mar  Toroiitoy.  'I'lic 
patchcH  of  tiinbiT  in  tin;  l)ackgroini(l  ocTtipy  tiic  wliady  Hidcn  ot  tiic  spiirH;  ilic  Hiinny 
Hlopps  ar"  graHH-covcrod ;  tlu;  valley  Moor  \-  lilli',1  with  lliickris  and  patclics  of  wood- 
land but  not  true  forest. 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        79 


The  one  is  forested,  the  other  grass-cov-. 
ered.  Slopes  that  receive  the  noon  and 
afternoon  sun  the  greater  part  of  the  year 
are  hottest  and  therefore  driest.  For 
places  in  11°  south  latitude  the  sun  is  well 
to  the  north  six  months  of  the  year,  nearly 
overhead  for  about  two  months,  and  to  the 
south  four  months.  Northwesterly  as- 
pects are  therefore  driest  and  warmest, 
hence  also  grass-covered.  In  many  places 
the  line  between  grass  and  forest  is  de- 
veloped so  sharply  that  it  seems  to  be  the 
artificial  edge  of  a  cut-over  tract.  This  is 
true  especially  if  the  relief  is  steep  and 
the  hill  or  ridge-crests  sharp.^ 

At  Santa  Ana  this  feature  is  developed 
in  an  amazingly  clear  manner,  and  it  is 
also  combined  with  the  dry  timber  line  and 
with  producti\ity  in  a  way  I  have  never 
seen  equaled  elsewhere.  The  diagram  will 
explain  the  relation.  It  will  be  seen  that 
the  front  range  of  the  mountains  is  high 
enough  to  shut  off  a  great  deal  of  rainfall. 
The  lower  hills  and  ridges  just  within  the 
front  range  are  relatively  dry.  The  deep 
valleys  are  much  drier.  Each  broad  ex- 
pansion of  a  deep  valley  is  therefore  a  dry 
pocket.     Into  it  the  sun  pours  even  when 

»  Marcoy  who  traveled  in  Peru  in  the  middle  of  the 
last  century  was  greatly  impressed  by  the  sympathetic 
changes  of  aspect  and  topography  and  vegetation  in  the 
eastern  valleys.  He  thus  describes  a  sudden  change  of 
scene  in  the  Occobamba  valley:  ".  .  .  the  trees  had  dis- 
appeared, the  birds  had  taken  Aving,  and  great  sandy 
spaces,  covered  with  the  latest  deposits  of  the  river,  al- 
ternated with  stretches  of  yellow  grass  and  masses  of 
rock  half-buried  in  the  ground."  (Travels  in  South 
America,  translated  by  Elihu  Rich,  2  vols.  New  York, 
1875,  Vol.  1,  p.  326.) 


■:i^ 


a 


o 


80  THE  ANDES  OF  SOUTHERN  PERU 

all  the  surrounding  hills  and  mountains  are  wrapped  in  cloud. 
The  greater  number  of  hours  of  sunshine  hastens  the  rate  of 
evaporation  and  still  further  increases  the  dryness.  Under  the 
spur  of  much  sunlight  and  of  ample  irrigation  water  from  the 
wetter  hill  slopes,  the  dry  valley  pockets  produce  huge  crops  of 
fruit  and  cane. 

The  influence  of  the  local  climate  upon  tree  growth  is  striking. 
Every  few  days,  even  in  the  relatively  dry  winter  season,  clouds 
gather  about  the  hills  and  there  are  local  showers.  The  lower 
limit  of  the  zone  of  clouds  is  sharply  marked  and  at  both  Santa 
Ana  and  Echarati  it  is  strikingly  constant  in  elevation — about 
five  thousand  feet  above  sea  level.  From  the  upper  mountains 
the  forest  descends,  with  only  small  patches  of  glade  and  prairie. 
At  the  lower  edge  of  the  zone  of  cloud  it  stops  abruptly  on  the 
warmer  and  drier  slopes  that  face  the  afternoon  sun  and  continues 
on  the  moister  slopes  that  face  the  forenoon  sun  or  that  slope 
away  from  the  sun. 

But  this  is  not  the  only  response  the  vegetation  makes.  The 
forest  changes  in  character  as  well  as  in  distribution.  The  forest 
in  the  wet  zone  is  dense  and  the  undergrowth  luxuriant.  In  the 
selective  slope  forest  below  the  zone  of  cloud  the  undergrowth  is 
commonly  thin  or  wanting  and  the  trees  grow  in  rather  even-aged 
stands  and  by  species.  Finally,  on  the  valley  floor  and  the  tribu- 
tary fans,  there  is  a  distinct  growth  of  scrub  with  bands  of  trees 
along  the  water  courses.  Local  tracts  of  coarse  soil,  or  less  rain 
on  account  of  a  deep  "hole"  in  a  valley  surrounded  by  steeper 
and  higher  mountains,  or  a  change  in  the  valley  trend  that  brings 
it  into  less  free  communication  with  the  prevailing  winds,  may 
still  further  increase  the  dryness  and  bring  in  a  true  xerophytic 
or  drought-resisting  vegetation.  Cacti  are  common  all  llnougli 
the  Santa  Ana  Valley  and  below  Sahuayaco  there  is  a  patch  of 
tree  cacti  and  similar  forms  several  square  miles  in  extent.  Still 
farther  down  and  about  lialf-way  l)etween  Sahuayaco  and  Pabol- 
lon  are  immense  tracts  of  grass-covered  mountain  slopes  (Fig. 
53).  These  extend  beyond  T?osalina,  the  last  of  them  terminating 
near  Abra  Tocate  (Fig.  15).    Tlie  sudden  interruption  is  due  to  a 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES 


81 


tlGOfffer 


charati 

SCALt  or  MILES 


turn  ill  the  valley  giving  freer  access  to  the  up-valley  winds  that 
sweep  through  the  pass  at  Pongo  de  Mainique. 

Northward  from  Abra  Tocate   (Fig.  55)    the  forest  is  prac- 
tically continuous.     The  break  between  the  tw^o  vegetal  regions 
is    emphasized    by    a    corral    for    cattle    and    mules,    the    last 
outpost    of    the    plateau 
herdsmen.      Not    three 
miles  away,  on  the  oppo- 
site forested  slope  of  the 
valley,  is  the  first  of  the 
Indian     clearings     where 
several  families  of  Machi- 
gangas  spend  the  wet  sea- 
son when  the  lower  river 
is  in  flood  (Fig.  21).    The 
grass  lands  will  not  yield 
corn  and  coca  because  the 
soil  is  too  thin,  infertile, 
and     dry.       The     Indian 
farms  are  therefore  all  in 
the   forest  and  begin  al- 
most   at    its    very    edge. 
Here  finally  terminates  a 
long  peninsula   of  grass- 
covered  country.    Below  this  point  the  heat  and  humidity  rapidly 
increase;  the  rains  are  heavier  and  more  frequent;  the  country 
becomes    almost   uninhabitable    for    stock;    transportation    rates 
double.    Here  is  the  undisputed  realm  of  the  forest  with  new  kinds 
of  trees  and  products  and  a  distinctive  type  of  forest-dwelling 
Indian. 

At  the  next  low  pass  is  the  skull  of  an  Italian  who  had  mur- 
dered his  companions  and  stolen  a  season's  picking  of  rubber,  at- 
tempting to  escape  by  canoe  to  the  low^er  Urubamba  from  the 
Pongo  de  Mainique.  The  Machigangas  overtook  him  in  their 
swiftest  dugouts,  spent  a  night  with  him,  and  the  next  morning 
shot  him  in  the  back  and  returned  with  their  rightful  property — 


Fig.  55 — Map  to  show  the  reUition  of  the 
grasslands  of  the  dry  lower  portion  of  the 
Urubamba  Valley  (unshaded)  to  the  forested 
lands  at  higher  elevations  (shaded).  See  Fig. 
54  for  climatic  conditions.  Patches  and  slender 
tongues  of  woodland  occur  below  the  main 
timber  line  and  patches  of  grassland  above  it. 


82  THE  ANDES  OF  SOUTHERN  PERU 

a  harvest  of  rubber.  For  more  than  a  decade  foreigners  have  been 
coming  down  from  the  plateau  to  exploit  them.  They  are  an  inde- 
pendent and  free  tribe  and  have  simple  yet  correct  ideas  of  right 
and  wrong.  Their  chief,  a  man  of  great  strength  of  character 
and  one  of  the  most  likeable  men  I  have  known,  told  me  that  he 
placed  the  skull  in  the  pass  to  warn  away  the  whites  who  came  to 
rob  honest  Indians. 

The  Santa  Ana  Valley  between  the  Canyon  of  Torontoy  and 
the  hea^^r  forest  belt  below  Eosalina  is  typical  of  many  of  the 
eastern  valleys  of  Peru,  both  in  its  phj^sical  setting  and  in  its 
economic  and  labor  systems.  Westward  are  the  outliers  of  the 
Vilcapampa  range;  on  the  east  are  the  smaller  ranges  that  front 
the  tropical  lowlands.  Steep  valleys  descend  from  the  higher 
country  to  join  the  main  valley  and  at  the  mouth  of  every  tribu- 
tary is  an  alluvial  fan.  If  the  alluvium  is  coarse  and  steeply  in- 
clined there  is  onl}^  pasture  on  it  or  a  growth  of  scrub.  If  fine  and 
broad  it  is  cleared  and  tilled.  The  sugar  plantations  begin  at 
Huadquina  and  end  at  Eosalina.  Those  of  Santa  Ana  and 
Echarati  are  the  most  productive.  It  takes  eighteen  months  for 
the  cane  to  mature  in  the  cooler  weather  at  Huadquina  (8,000  feet). 
Less  than  a  year  is  required  at  Santa  Ana  (3,400  feet).  Patches 
of  alluvium  or  playas,  as  they  are  locally  called,  continue  as  far 
as  Santo  Anato,  but  they  are  cultivated  only  as  far  as  Eosalina. 
The  last  large  plantation  is  Pabellon;  the  largest  of  all  is  Echarati, 
All  are  irrigated.  In  the  wet  months,  December  to  March  inclu- 
sive, tliere  is  little  or  no  irrigation.  In  the  four  months  of  the  dry 
season,  June  to  September  inclusive,  there  is  frequent  irrigation. 
Since  the  cane  matures  in  about  ten  months  the  harvest  seasons 
fall  irregularly  with  respect  to  the  seasons  of  rain.  Therefore  the 
land  is  cleared  and  planted  at  irregular  intervals  and  labor  dis- 
tributed sf)iM('\vli;il  lliiough  the  year.  There  is  however  a  concen- 
tration of  l.'ibor  1()\v;ii<l  llif  cud  of  the  dry  season  when  most  of 
the  cauf  is  cut  for  grinding. 

Tlio  combined  freiglit  rate  and  government  tax  on  coca,  sugar, 
and  brandy  take  a  large  part  of  all  that  the  planter  can  get  for 
his  crop.    It  is  120  miles  (190  km.)  from  Santa  Ana  to  Cuzco  and 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        83 

it  takes  five  days  to  make  the  journey.  The  freight  rate  on  coca 
and  sugar  for  mule  carriage,  the  only  kind  to  be  had,  is  two  cents 
per  pound.  The  national  tax  is  one  cent  per  pound  (0.45  kg.). 
The  coca  sells  for  twenty  cents  a  pound.  The  cost  of  production 
is  unknown,  but  the  paid  labor  takes  probably  one-half  this 
amount.  The  planter's  time,  capital,  and  profit  must  come  out 
of  the  rest.  On  brandy  there  is  a  national  tax  of  seven  cents  per 
liter  (0.26  gallon)  and  a  municipal  tax  of  two  and  a  half  cents. 
It  costs  five  cents  a  liter  for  transport  to  Cuzco.  The  total  in 
taxes  and  transport  is  fourteen  and  a  half  cents  a  liter.  It  sells 
for  twenty  cents  a  liter.  Since  brandy  (aguardiente),  cacao  (for 
chocolate),  and  coca  leaves  (for  cocaine)  are  the  only  precious  sub- 
stances which  the  valleys  produce  it  takes  but  a  moment's  inspec- 
tion to  see  how  onerous  these  taxes  would  be  to  the  planter  if 
labor  did  not,  as  usual,  pay  the  penalty. 

Much  of  the  labor  on  the  plantations  is  free  of  cost  to  the 
owner  and  is  done  by  the  so-called  faena  or  free  Indians.  These 
are  Quechuas  who  have  built  their  cabins  on  the  hill  lands 
of  the  planters,  or  on  the  floors  of  the  smaller  valleys.  The  dis- 
position of  their  fields  in  relation  to  the  valley  plantations  is  full 
of  geographic  interest.  Each  plantation  runs  at  right  angles  to 
the  course  of  the  valley.  Hacienda  Sahuayaco  is  ten  miles  (16 
km.)  in  extent  down  valley  and  forty  miles  (64  km.)  from  end  to 
end  across  the  valley,  and  it  is  one  of  the  smaller  plantations !  It 
follows  that  about  ten  square  miles  lie  on  the  valley  floor  and  half 
of  this  can  ultimately  be  planted.  The  remaining  three  hundred 
and  ninety  square  miles  include  some  mountain  country  with  pos- 
sible stores  of  mineral  wealth,  and  a  great  deal  of  "fells"  coun- 
try— grassy  slopes,  graded  though  steep,  excellent  for  pasture, 
with  here  and  there  patches  of  arable  land.  But  the  hill  country 
can  be  cultivated  only  by  the  small  farmer  who  supplements  his 
supply  of  food  from  cultivated  plants  like  potatoes,  corn,  and 
vegetables,  by  keeping  cattle,  mules,  pigs,  and  poultry,  and  by 
raising  coca  and  fruit. 

The  Indian  does  not  own  any  of  the  land  he  tills.  He  has  the 
right  merely  to  live  on  it  and  to  cultivate  it.     In  return  he  must 


84  THE  ANDES  OF  SOUTHERN  PERU 

work  a  certain  number  of  days  each  year  on  the  owner's  planta- 
tion. In  many  cases  a  small  money  payment  is  also  made  to  the 
planter.  The  planter  prefers  labor  to  money,  for  hands  are 
scarce  throughout  the  whole  eastern  valley  region.  No  Indian 
need  work  on  the  planter's  land  without  receiving  pay  directly 
therefor.  Each  also  gets  a  small  weekly  allotment  of  aguardiente 
while  in  the  planter's  employ. 

The  scene  eveiy  Saturday  night  outside  the  office  of  the  con- 
tador  (treasurer)  of  a  plantation  is  a  novel  one.  Several  hundred 
Indians  gather  in  the  dark  patio  in  front  of  the  office.  Within 
the  circle  of  the  feeble  candlelight  that  reaches  only  the  margin 
of  the  crowd  one  may  see  a  pack  of  heavy,  perspiring  faces.  Many 
are  pock-marked  from  smallpox ;  here  and  there  an  eye  is  missing ; 
only  a  few  are  jo\dal.  A  name  is  shouted  through  the  open  door 
and  an  Indian  responds.  He  pulls  off  his  cap  and  stands  stupid 
and  blinking,  while  the  contador  asks : 

"Faena"  (free)? 

"Si,  Senor,"  he  answers. 

'*Un  sol"  (one  "sol"  or  fifty  cents  gold).  The  assistant  hands 
over  the  money  and  the  man  gives  way  to  the  next  one  on  the  list. 
If  he  is  a  laborer  in  regular  and  constant  employ  he  receives  five 
soles  (two  fifty  gold)  per  week.  There  are  interruptions  now  and 
then.  A  ragged,  half-dninken  man  has  been  leaning  against  the 
door  post,  suspiciously  impatient  to  receive  his  money.  Finally 
his  name  is  called. 

"Faena?"  asks  the  conlador. 

"No,  Sefior,  cinco  (five)  soles." 

At  that  the  field  superintendente  glances  at  liis  time  card  and 
speaks  up  in  protest. 

"You  were  the  man  that  failc*!  jo  sliow  uj)  on  l"'i-i(lay  and  Sat- 
urday,    ^'itu  were  di-iiiik.     ^'()ll  slioiild  receive  nothing." 

"No,  mi  pal  roll,"  the  man  contends,  "1  had  to  visit  a  sick 
fonsin  in  tlie  iie\1  \alley.  ( )]i,  lie  was  very  sick,  Scfior,"  and  he 
conglis  liarslily  as  if  lie  too  were  on  the  verge  of  pi'oatration.  Tlie 
sick  cousin,  a  faona  Indian,  has  been  at  work  in  another  cane  field 
on  the  same  plantation  for  two  days  and  now  calls  out  that  he  is 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        85 

present  and  has  never  had  a  sick  day  in  his  life.  Those  outside 
laugh  uproariously.  The  contador  throws  down  two  soles  and 
the  drunkard  is  pushed  back  into  the  sweating  crowd,  jostled 
right  and  left,  and  jeered  by  all  his  neighbors  as  he  slinks  away 
grumbling. 

Another  Indian  seems  strangely  shy.  He  scarcely  raises  his 
voice  above  a  whisper.  He  too  is  a  faena  Indian.  The  contador 
finds  fault. 

''Why  didn't  you  come  last  month  when  I  sent  for  you  I" 

The  Indian  fumbles  his  cap,  shuffles  his  feet,  and  changes  his 
coca  cud  from  one  bulging  cheek  to  the  other  before  he  can  an- 
swer.    Then  huskily: 

''I  started,  Senor,  but  my  w^oman  overtook  me  an  hour  after- 
ward and  said  that  one  of  the  ew^es  had  dropped  a  lamb  and 
needed  care." 

' '  But  your  woman  could  have  tended  it ! " 

"No,  Seiior,  she  is  sick." 

"How,  then,  could  she  have  overtaken  you?"  he  is  asked. 

' '  She  ran  only  a  little  way  and  then  shouted  to  me. ' ' 

"And  what  about  the  rest  of  the  month?"  persists  the  contador. 

"The  other  lambs  came,  Seiior,  and  I  should  have  lost  them 
all  if  I  had  left." 

The  contador  seems  at  the  end  of  his  complaint.  The  Indian 
promises  to  w^ork  overtime.  His  difficulties  seem  at  an  end,  but 
the  superintendent  looks  at  his  old  record. 

"He  always  makes  the  same  excuse.  Last  year  he  was  three 
weeks  late." 

So  the  poor  shepherd  is  fined  a  sol  and  admonished  that  his 
lands  will  be  given  to  some  one  else  if  he  does  not  respond  more 
promptly  to  his  patron's  call  for  work.  He  leaves  behind  him  a 
promise  and  the  rank  mixed  smell  of  coca  and  much  unwashed 
woolen  clothing. 

It  is  not  alone  at  the  work  that  they  grumble.  There  is  ma- 
laria in  the  lower  valleys.  Some  of  them  return  to  their  lofty 
mountain  homes  prostrated  with  the  unaccustomed  heat  and  alter- 
nately shaking  with  chills  and  burning  with  fever.  -  Without  aid 


86  THE  ANDES  OF  SOUTHERN  PERU 

they  may  die  or  become  so  weakened  that  tuberculosis  carries 
them  off.  Only  their  rugged  strength  enables  the  greater  number 
to  return  in  good  health. 

A  plantation  may  be  as  large  as  a  principality  and  draw  its 
laborers  from  places  fifty  miles  away.  Some  of  the  more  distant 
Indians  need  not  come  to  work  in  the  canefields.  Part  of  their 
flock  is  taken  in  place  of  work.  Or  they  raise  horses  and  mules 
and  bring  in  a  certain  number  each  year  to  turn  over  to  the 
patron.  Hacienda  Huadquiiia  (Fig.  46)  takes  in  all  the  land  from 
the  snow-covered  summits  of  the  Cordillera  Vilcapampa  to  the 
canefields  of  the  Urubamba.  Within  the  broad  domain  are  half 
the  climates  and  occupations  characteristic  of  Peru.  It  is  diffi- 
cult to  see  how  a  thousand  Indians  can  be  held  to  even  a  mixed 
allegiance. '  It  seems  impossible  that  word  can  be  got  to  them. 
However  the  native  "telegraph"  is  even  more  perfect  than  that 
among  the  forest  Indians.  From  one  to  the  other  runs  the  news 
that  they  are  needed  in  the  canefields.  On  the  trail  to  and  from 
a  mountain  village,  in  their  ramblings  from  one  high  pasture  to 
another,  within  the  dark  walls  of  their  stone  and  mud  huts  when 
they  gather  for  a  feast  or  to  exchange  drinks  of  brandy  and 
chicha — the  word  is  passed  that  has  come  up  from  the  valleys. 

For  every  hundred  faena  Indians  there  are  five  or  six  regular 
laborers  on  the  plantations,  so  with  the  short  term  passed  by  the 
faoii.i  Indians  their  number  is  generally  half  that  of  the  total 
laborers  at  work  at  any  one  time.  They  live  in  huts  provided  for 
them  by  the  planter,  and  in  the  houses  of  their  friends  among  the 
regular  lal)orors.  Here  there  are  almost  nightly  carousals.  The 
reguhir  hiborcr  comes  from  the  city  or  the  valley  town.  The  faena 
laborer  is  a  small  hill  farmer  or  shepherd.  They  have  much  to 
exchange  in  llic  way  oi"  (•lolhing,  food,  and  news.  I  have  fre- 
(|ti<'iilly  had  their  conNci-sal  ions  iiilci'pi-otcd  for  mo.  They  ask 
about,  tiic  flocks  and  tlx-  childi-cn,  who  i)ass('d  along  the  trails,  what 
accidents  bofcll  the  people. 

"Last  year,"  droned  one  to  another  oxer  their  chicha,  "last 
year  we  lost  three  lanihs  in  a  hailstorm  up  in  the  high  fields  near 
the  snow.     It  was  very  cold.     My  foot  cracked  open  and,  though 


THE  BORDER  VALLEYS  OF  THE  EASTERN  ANDES        87 

I  have  bound  it  with  wet  coca  leaves  every  night,  it  will  not  cure," 
and  he  displays  his  heel,  the  skin  of  which  is  like  horn  for  hard- 
ness and  covered  with  a  crust  of  dirt  whose  layers  are  a  record 
of  the  weather  and  of  the  pools  he  has  waded  for  years. 

Their  wanderings  are  the  main  basis  of  conversation.  They 
know  the  mountains  better  than  the  condors  do.  We  hired  a  small 
boy  of  twelve  at  Puquiura.  He  was  to  build  our  fires,  carry  water, 
and  help  drive  the  mules.  He  crossed  the  Cordillera  Vilcapampa 
on  foot  with  us.  He  scrambled  down  into  the  Apurimac  canyon 
and  up  the  ten  thousand  feet  of  ascent  on  the  other  side,  twisted 
the  tails  of  the  mules,  and  shouted  more  vigorously  then  the  ar- 
rieros.  He  was  engaged  to  go  with  us  to  Pasaje,  where  his  father 
would  return  with  him  in  a  month.  But  he  climbed  to  Huascatay 
with  us  and  said  he  wanted  to  see  Abancay.  When  an  Indian 
whom  we  pressed  into  service  dropped  the  instruments  on  the 
trail  and  fled  into  the  brush  the  boy  packed  them  like  a  man.  The 
soldier  carried  a  tripod  on  his  back.  The  boy,  not  to  be  outdone, 
insisted  on  carrying  the  plane  table,  and  to  his  delight  we  called 
him  a  soldier  too.  He  went  with  us  to  Huancarama.  When  I  paid 
him  he  smiled  at  the  large  silver  soles  that  I  put  into  his  hand; 
and  when  I  doubled  the  amount  for  his  willingness  to  work  his  joy 
was  unbounded.  Forthwith  he  set  out,  this  time  on  muleback,  on 
the  return  journey.  The  last  I  saw  of  him  he  was  holding  his 
precious  soles  in  a  handkerchief  and  kicking  his  beast  with  his 
bare  heels,  as  light-hearted  as  a  cavalier.  Often  I  find  myself  won- 
dering whether  he  returned  safely  with  his  money.  I  should  very 
much  like  to  see  him  again,  for  with  him  I  associate  cheerfulness 
in  difficult  places  and  many  a  pleasant  camp-fire. 


CHAPTER  VII 

THE  GEOGRAPHIC  BASIS  OF  REVOLUTIONS  AND  OF  HUMAN 
CHARACTER  IN  THE  PERUVIAN  ANDES 

Human  character  as  a  spontaneous  development  has  always 
been  a  great  factor  in  shaping  historical  events,  but  it  is  a  strik- 
ing fact  that  in  the  world  of  our  day  its  influence  is  exerted  chiefly 
in  the  lowest  and  highest  types  of  humanity.  The  savage  with 
his  fetishes,  his  taboos,  and  his  inherent  childlikeness  and  suspi- 
cion needs  only  whim  or  a  slight  religious  pretext  to  change  his 
conduct.  Likewise  the  really  educated  and  the  thoughtful  act  from 
motives  often  wholly  unrelated  to  economic  conditions  or  results. 
But  the  masses  are  deeply  influenced  by  whatever  affects  their 
material  welfare.  A  purely  idealistic  impulse  may  influence  a 
people,  but  in  time  its  effects  are  always  displayed  against  an  eco- 
nomic background. 

There  is  a  way  whereby  we  may  test  this  theory.  In  most 
places  in  the  world  we  have  history  in  the  making,  and  through 
field  studies  we  can  get  an  intimate  view  of  it.  It  is  peculiarly 
the  province  of  geography  to  study  the  present  distribution 
and  character  of  men  in  relation  to  their  surroundings  and 
these  are  the  facts  of  mankind  that  must  forever  be  the  chief 
data  of  economic  history.  It  is  not  vain  repetition  to  say  that  this 
means,  first  of  all,  the  study  of  the  character  of  men  in  the  fullest 
sense.  It  means,  in  the  second  place,  that  a  large  part  of  the  char- 
acter nuist  be  really  und<'rstood.  Whenever  this  is  done  there  is 
found  a  geographic  basis  of  human  character  lliai  is  capable  of  the 
clearest  (Iciiioiislralion.  It  is  in  Die  geographic  environment  that 
the  matfrijil  iimlivcs  of  lmin;mity  liave  struck  llu'ir  deepest  roots. 

These  conclusions  miglil  1m'  illustrated  from  a  hundred  places 
in  the  (ifld  of  study  covered  in  this  book.  Almost  every  chapter 
of  Part  i  contains  facts  of  this  eliaract.T.     I  wisli,  however,  to  dis- 

88 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER   89 

cuss  the  subject  specifically  and  for  that  purpose  now  turn  to  the 
conditions  of  life  in  the  remoter  mountain  valleys  and  to  one  or 
two  aspects  of  the  revolutions  that  occur  now  and  then  in  Peru. 
The  last  one  terminated  only  a  few  months  before  our  arrival  and 
it  was  a  comparatively  easy  matter  to  study  both  causes  and 
effects. 

A  caution  is  necessary  however.  It  is  a  pity  that  we  use  the 
term  "revolution"  to  designate  these  little  disturbances.  They 
affect  sometimes  a  few,  again  a  few  hundred  men.  Rarely  do 
they  involve  the  whole  country.  A  good  many  of  them  are  on  a 
scale  much  smaller  than  our  big  strikes.  Most  of  them  involve 
a  loss  of  life  smaller  than  that  which  accompanies  a  city  riot.  They 
are  in  a  sense  strikes  against  the  government,  marked  by  local  dis- 
orders and  a  little  violence. 

Early  in  1911  the  Prefect  of  the  Department  of  Abancay  had 
crowned  his  long  career  by  suppressing  a  revolution.  He  had 
been  Subprefect  at  Andahuaylas,  and  when  the  rebels  got  control 
of  the  city  of  Abancay  and  destroyed  some  of  the  bridges  on  the 
principal  trails,  he  promptly  organized  a  military  expedition,  con- 
structed rafts,  floated  his  small  force  of  men  across  the  streams, 
and  besieged  the  city.  The  rebel  force  was  driven  at  last  to  take 
shelter  in  the  city  jail  opposite  the  Prefectura.  There,  after  the 
loss  of  half  their  number,  they  finally  surrendered.  Seventy-five 
of  them  were  sent  to  the  government  penitentiary  at  Arequipa. 
Among  the  killed  were  sons  from  nearly  half  the  best  families  of 
Abancay.    All  of  the  rebels  were  young  men. 

It  would  be  difficult  to  give  an  adequate  idea  of  the  hatred  felt 
by  the  townspeople  toward  the  government.  Every  precaution 
was  taken  to  prevent  a  renewal  of  the  outbreak.  Our  coming  was 
telegraphed  ahead  by  government  agents  who  looked  with  suspi- 
cion upon  a  party  of  men,  well  armed  and  provisioned,  coming  up 
from  the  Pasaje  crossing  of  the  Apurimac,  three  days'  journey 
north.  The  deep  canyon  affords  shelter  not  only  to  game,  but  also 
to  fugitives,  rebels,  and  bandits.  The  government  generally 
abandons  pursuit  on  the  upper  edge  of  the  canyon,  for  only  a  pro- 
longed guerilla  warfare  could  completely  subdue  an  armed  force 


90  THE  ANDES  OF  SOUTHERN  PERU 

scattered  along  its  rugged  walls  and  narrow  floor.  The  owner  of 
the  hacienda  at  Pasaje  is  required  to  keep  a  record  of  all  passen- 
gers rafted  across  the  Apurimac,  but  he  explains  significantly  that 
some  who  pass  are  too  hurried  to  write  their  names  in  his  book. 
Once  he  reaches  the  eastern  wall  of  the  canyon  a  fugitive  may 
command  a  view  of  the  entire  western  wall  and  note  the  approach 
of  pursuers.  Thence  eastward  he  has  the  whole  Cordillera  Vilca- 
pampa  in  which  to  hide.    Pursuit  is  out  of  the  question. 

When  we  arrived,  the  venerable  Prefect,  a  model  of  old-fash- 
ioned courtesy,  greeted  us  with  the  utmost  cordiality.  He  told  us 
of  our  movements  since  leaving  Pasaje,  and  laughingly  explained 
that  since  we  had  sent  him  no  friendly  message  and  had  come 
from  a  rebel  retreat,  he  had  taken  it  for  granted  that  we  intended 
to  storm  the  town.  I  assured  him  that  we  were  ready  to  join  his 
troops,  if  necessary,  whereupon,  with  a  delightful  frankness,  he 
explained  his  method  of  keeping  the  situation  in  hand.  Several 
troops  of  cavalry  and  two  battalions  of  infantry  were  quartered 
at  the  government  barracks.  Every  evening  the  old  gentleman, 
a  Colonel  in  the  Peruvian  army,  mounted  a  powerful  gray  horse 
and  rode,  quite  unattended,  through  the  principal  streets  of  the 
towTi.  Several  times  I  walked  on  foot  behind  him,  again  I  pre- 
ceded him,  stopping  in  shops  on  the  way  to  make  trivial  purchases, 
to  find  out  what  the  people  had  to  say  about  him  and  the  govern- 
ment as  he  rode  by.  One  old  gentleman  interested  me  particularly, 
lie  had  only  the  day  before  called  at  the  Prefectura  to  pay  his 
respects.  Although  his  manner  was  correct  there  was  lacking  to 
a  noticeable  degree  the  profusion  of  sentiment  that  is  apt  to  be 
exhibited  on  such  [in  occasion.  He  now  sat  on  a  bench  in  a  shop. 
Both  his  own  son  and  the  shopkeeper's  son  had  been  slain  in  the 
revolution.  It  was  natural  Ihnt  they  should  be  bitter.  But  the 
precise  nature  of  Ihcir  (•(uiiiil.-iiiil  \v;is  wliat  interested  me  most. 
One  said  that  lie  did  not  o])J('c1  lo  liiniiiii:  liis  son  lose  his  life  for 
Ills  country.  I'lii  tliat  his  ronntry's  olTicials  slionid  liiro  Indians 
to  slioot  liis  sf)n  Kccmcd  to  him  sheer  mui-dcr.  Later,  at  Lam- 
brama,  T  talkod  with  a  robol  fugitive,  and  that  was  also  his  com- 
plaint.    The  young  men  drafted  into  the  army  are  Indians,  or 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER        91 

mixed,  never  whites.  White  men,  and  men  with  a  small  amount 
of  Indian  blood,  officer  the  army.  When  a  revolutionary  party 
organizes  it  is  of  course  made  up  wholly  of  men  of  white  and 
mixed  blood,  never  Indians.  The  Indians  have  no  more  grievance 
against  one  white  party  than  another.  Both  exploit  him  to  the 
limit  of  law  and  beyond  the  limit  of  decency.  He  fights  if  he  must,  / 
but  never  by  choice. 

Thus  Indian  troops  killed  the  white  rebels  of  Abancay. 

"Tell  me,  Sefior,"  said  the  fugitive,  "if  you  think  that  just. 
Tell  me  how  many  Indians  you  think  a  white  man  worth.  Would 
a  hundred  dead  Indians  matter?  But  how  replace  a  white  man 
where  there  are  so  few?  The  government  assassinated  my  com- 
patriots ! " 

"But,"  I  replied,  "why  did  you  fight  the  government?  All  of 
you  were  prosperous.  Your  fathers  may  have  had  a  grievance 
against  the  government,  but  of  what  had  you  young  men  to  com- 
plain?" 

His  reply  was  far  from  convincing.  He  was  at  first  serious,  but 
his  long  abstract  statements  about  taxes  and  government  waste- 
fulness trailed  off  into  vagueness,  and  he  ended  in  a  laughing 
mood,  talking  about  adventure,  the  restless  spirit  of  young  men, 
and  the  rich  booty  of  confiscated  lands  and  property  had  the 
rebels  won.  He  admitted  that  it  was  a  reckless  game,  but  when  I 
called  him  a  mere  soldier  of  fortune  he  grew  serious  once  more 
and  reverted  to  the  iniquitous  taxation  system  of  Peru.  Further 
inquiry  made  it  quite  clear  that  the  ill-fated  revolution  of  Abancay 
.was  largely  the  work  of  idle  young  men  looking  for  adventure. 
It  seemed  a  pity  that  their  splendid  physical  energy  could  not 
have  been  turned  into  useful  channels.  The  land  sorely  needs  en- 
gineers, progressive  ranchmen  and  farmers,  upright  officials,  and 
a  spirit  of  respect  for  law  and  order.  Old  men  talked  of  the  un- 
stable character  of  the  young  men  of  the  time,  but  almost  all  of 
them  had  themselves  been  active  participants  in  more  than  one 
revolution  of  earlier  years. 

Every  night  at  dinner  the  Prefect  sent  off  by  government  tele- 
graph a  long  message  to  the  President  of  the  Eepublic  on  the 


92  THE  ANDES  OF  SOUTHERN  PERU 

state  of  the  Department,  and  received  similar  messages  from  the 
central  government  about  neighboring  departments.  These  he 
read  to  us,  and,  curiously  enough,  to  the  entire  party,  made  up 
of  army  officers  and  townsmen,  I  was  surprised  to  find  later  that 
the  company  included  one  government  official  whose  son  had  been 
among  the  imprisoned  rebels  at  Arequipa.  We  met  the  young 
man  a  week  later  at  a  mountain  village,  a  day  after  a  general 
amnesty  had  been  declared.  His  escape  had  been  made  from  the 
prison  a  month  before.  He  forcibly  substituted  the  mess-boy's 
clothing  for  his  ow^n,  and  thus  passed  out  unnoticed.  After  a  few 
days '  hiding  in  the  city,  he  set  out  alone  across  the  desert  of  Vitor, 
thence  across  the  lofty  volcanic  country  of  the  Maritime  Andes, 
through  some  of  the  most  deserted,  inhospitable  land  in  Peru,  and 
at  the  end  of  three  weeks  had  reached  Lambrama,  near  Abancay, 
the  picture  of  health ! 

Later  I  came  to  have  a  better  notion  of  the  economic  basis  of 
the  revolution,  for  obviously  the  planters  and  the  reckless  young 
men  must  have  had  a  mutual  understanding.     Somewhere  the 
rebels  had  obtained  the  sinews  of  war.    The  planters  did  not  take 
an  open  part  in  the  revolution,  but  they  financed  it.    When  the 
rebels  were  crushed,  the  planters,  at  least  outwardly,  welcomed 
the  government  forces.     Inwardly  they  cursed  them  for  thwart- 
ing their  scheme.     The  reasons  have  an  interesting  geographic 
basis.    Abancay  is  the  center  of  a  sugar  region.    Great  irrigated 
estates  are  spread  out  along  the  valley  floor  and  the  enormous  al- 
luvial fans  built  into  the  main  valley  at  the  mouths  of  the  tribu- 
tary streams.    There  is  a  heavy  tax  on  sugar  and  on  aguardiente 
(brandy)   manufactured  from  cane  juice.     The  hacendados  had 
dreamf'd  of  lighter  taxes.    The  rebels  offered  the  means  of  secur- 
ing relief.    But  taxes  were  not  the  real  reason  for  the  unrest,  for 
many  other  sugar  producers  pay  the  tax  without  serious  com- 
j)l;iiiit.     A});iiif'ay  is  cu\  <){"(  from  flio  rest  of  Peru  by  great  moun- 
tains.   Toward  ilie  west,  via  Antabamba,  Cotahuasi,  and  Thuqui- 
bamba,  two  liundrr-d  milos  of  trail  separato  its  plantations  from 
the  Pacific.     Twelve  days'  hnrd  riding  is  required  to  reach  Limn 
over  the  old  colonial  trade  route.    Tt  is  three  days  to  Cuzco  at  the 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER        93 

end  of  the  three-hundred-mile  railway  from  the  port  of  MoUendo. 
The  trails  to  the  Atlantic  rivers  are  impossible  for  trading  pur- 
poses. Deep  sunk  in  a  subtropical  valley,  the  irrigable  alluvial 
land  of  Abancay  tempts  the  production  of  sugar. 

But  nature  offers  no  easy  route  out  of  the  valley.  For  cen- 
turies the  product  has  been  exported  at  almost  prohibitive  cost, 
as  in  the  eastern  valley  of  Santa  Ana.  The  coastal  valleys 
enjoy  easy  access  to  the  sea.  Each  has  its  own  port  at  the 
valley  mouth,  where  ocean  steamers  call  for  cargo.  Many  have 
short  railway  lines  from  port  to  valley  head.  The  eastern 
valleys  and  Abancay  have  been  clamoring  for  railways,  better 
trails,  and  w^agon  roads.  From  the  public  fund  they  get  what 
is  left.  The  realization  of  their  hopes  has  been  delayed  too 
long.  It  would  be  both  economic  and  military  strategy  to  give 
them  the  desired  railway.  Revolutions  in  Peru  always  start 
in  one  of  two  ways :  either  by  a  coup  at  Lima  or  an  unchecked 
uprising  in  an  interior  province.  Bolivia  has  shown  the  way 
out  of  this  difficulty.  Two  of  her  four  large  centers — La  Paz 
and  Oruro — are  connected  by  rail,  and  the  line  to  Cochabamba 
lacks  only  a  few  kilometres  of  construction.^  To  Sucre  a  line  has 
been  long  projected.  Formerly  a  revolution  at  one  of  the  four 
to^^Tis  was  exceedingly  difficult  to  stamp  out.  Diaz  had  the  same 
double  motive  in  encouraging  railway  building  in  the  remote  des- 
ert provinces  of  Northern  Mexico,  where  nine  out  of  ten  Mexican 
revolutions  gather  headway.  Argentina  has  enjoyed  a  high  degree 
of  political  unity  since  her  railway  system  was  extended  to 
Cordoba  and  Tucuman.  The  last  uprising,  that  of  1906,  took  place 
on  her  remotest  northeastern  frontier. 

We  had  ample  opportunity  to  see  the  hatred  of  the  rebels.  At 
nightfall  of  September  25th  we  rode  into  the  courtyard  of  Haci- 
enda Auquibamba.     We  had  traveled  under  the  worst  possible 

•According  to  the  latest  information  (August,  1916)  of  the  Bolivia  IlTihvay  Co.. 
trains  are  running  from  Oruro  to  Buen  Retiro,  35  km.  from  Cochabamba.  Thence 
connection  with  Cochabamba  is  made  by  a  tram-line  operated  by  the  Electric  Light  and 
Power  Co.  of  that  city.  The  Bulletin  of  the  Pan-American  Union  for  July,  1916, 
also  reports  the  proposed  introduction  of  an  automobile  service  for  conveyance  of 
freight  and  passengers. 


9i  THE  ANDES  OF  SOUTHERN  PERU 

circumstances.  Our  mules  had  been  enfeebled  by  hot  valley 
work  at  Santa  Ana  and  the  lower  Urubamba  and  the  cold  moun- 
tain climate  of  the  Cordillera  Vilcapampa.  The  climb  out  of  the 
Apurimac  canyon,  even  without  packs,  left  them  completely  ex- 
hausted. AVe  were  obliged  to  abandon  one  and  actually  to  pull 
another  along.  It  had  been  a  hard  day  in  spite  of  a  prolonged 
noon  rest.  Everywhere  our  letters  of  introduction  had  won 
an  outpouring  of  hospitality  among  a  people  to  whom  hospitality 
is  one  of  the  strongest  of  the  unwritten  laws  of  society.  Our  sol- 
dier escort  rode  ahead  of  the  pack  train. 

As  the  clatter  of  his  mules'  hoofs  echoed  through  the  dark 
buildings  the  manager  rushed  out,  struck  a  light  and  demanded 
'* Who's  there?"  To  the  soldier's  cheerful  "Buena  noche,  Senor," 
he  sneeringly  replied  ' '  Halto !  Guardia  de  la  Republica,  aqui  hay 
nada  para  un  soldado  del  gobierno."  Whereupon  the  soldier 
turned  back  to  me  and  said  we  should  not  be  able  to  stop  here, 
and  coming  nearer  me  he  whispered  ''He  is  a  revolutionary." 
I  dismounted  and  approached  the  haughty  manager,  who  was 
in  a  really  terrible  mood.  Almost  before  I  could  begin  to 
ask  him  for  accommodations  he  rattled  off  that  there  was  no 
pasture  for  our  beasts,  no  food  for  us,  and  that  we  had  better 
go  on  to  the  next  hacienda.  "Absolutamente  nada!"  he  re- 
peated over  and  over  again,  and  at  first  I  thought  him  drunk. 
Since  it  was  then  quite  dark,  with  no  moon,  but  instead  heavy 
black  clouds  over  the  southern  half  of  the  sky  and  a  brisk  valley 
wind  threatening  rain,  I  mildly  protested  that  we  needed  noth- 
ing more  than  shelter.  Our  food  boxes  would  supply  our  wants, 
and  oui-  mules,  even  without  fodder,  could  reach  Abancay  the 
next  day.  SI  ill  lio  stormed  at  the  government  and  would  have 
none  of  us.  I  icminded  him  that  his  fields  were  filled  with 
sugar  fane  and  lliat  it  was  the  staple  forage  for  beasts  during 
the  ]»art.  of  the  year  when  paslurc  was  scarce.  The  cane  was 
too  valnable,  he  said.  It  was  impossible  to  supply  us.  I  was  on 
the  ])(.iii1  of  pitching  camp  bosido  Ihc  1i-ail,  U)v  it  was  impossible 
to  r^afh  tlif  next  hacienda  with  an  exhausted  outfit. 

Just  llu'n  an  older  man  stopped  into  the  circle  of  ligld  and  ami- 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER        95 

ably  inquired  the  purpose  of  our  journey.    When  it  was  explained, 
he  turned  to  the  other  and  said  it  was  unthinkable  that  men  should 
be  treated  so  inhospitably  in  a  strange  land.    Though  he  himself 
was  a  guest  he  urged  that  the  host  should  remember  the  laws  of 
hospitality,  whereupon  the  latter  at  last  grudgingly  asked  us  to  join 
him  at  his  table  and  to  turn  our  beasts  over  to  his  servants.    It  was 
an  hour  or  more  before  he  would  exhibit  any  interest  in  us.    AYhen 
he  had  learned  of  our  object  in  visiting  Abancay  he  became  some- 
what more  friendly,  though  his  hostility  still  manifested  itself. 
Nowhere  else  in  South  America  have  I  seen  exhibited  such  boorish 
conduct.    Nevertheless  the  next  morning  I  noticed  that  our  mules 
had  been  well  fed.    He  said  good-by  to  us  as  if  he  were  glad  to 
be  rid  of  any  one  in  any  way  connected  with  the  hostile  govern- 
ment.   Likewise  the  manager  at  Hacienda  Pasaje  held  out  almost 
until  the  last  before  he  would  consent  to  aid  us  with  fresh  beasts. 
Finally,  after  a  day  of  courting  I  gave  him  a  camp  chair.    He  was 
so  pleased  that  he  not  only  gave  us  beasts,  but  also  a  letter  of 
introduction  to  one  of  his  caretakers  on  a  farm  at  the  top  of  the 
cuesta.    Here  on  a  cold,  stormy  night  we  found  food  and  fuel  and 
the  shelter  of  a  friendly  roof. 

A  by-product  of  the  revolution,  as  of  all  revolutions  in  thinly 
settled  frontier  regions,  was  the  organization  of  small  bands  of 
outlaws  who  infested  the  lonely  trails,  stole  beasts,  and  left  their 
owners  robbed  and  helpless  far  from  settlements.  We  were  cau- 
tioned to  beware  of  them,  both  by  Senor  Gonzales,  the  Prefect  at 
Abancay,  and  by  the  Subprefect  of  Antabamba.  Since  some  of 
the  bandits  had  been  jailed,  I  could  not  doubt  the  accuracy  of  the 
reports,  but  I  did  doubt  stories  of  murder  and  of  raids  by  large 
companies  of  mountain  bandits.  As  a  matter  of  fact  we  were 
robbed  by  the  Governor  of  Antabamba,  but  in  a  way  that  did  not 
enable  us  to  find  redress  in  either  law  or  lead.  The  story  is  worth 
telling  because  it  illustrates  two  important  facts:  first,  the  vile 
so-called  government  that  exists  in  some  places  in  the  really 
remote  sections  of  South  America,  and  second,  the  character  of 
the  mountain  Indians. 

The  urgent  letter  from  the  Prefect  of  Abancay  to  the  Sub- 


96  THE  ANDES  OF  SOUTHERN  PERU 

prefect  of  Antabamba  quickly  brought  the  latter  from  his  distant 
home.  AVhen  we  arrived  we  found  him  drinking  with  the  Gov- 
ernor. The  Subprefect  was  most  courteous.  The  Governor  was 
good-natured,  but  his  face  exhibited  a  rare  combination  of  cruelty 
and  vice.  We  were  offered  quarters  in  the  municipal  building  for 
the  day  or  two  that  we  were  obliged  to  stop  in  the  town.  The 
delay  enabled  us  to  study  the  valley  to  w^hich  particular  interest 
attaches  because  of  its  situation  in  the  mountain  zone  between 
the  lofty  pastures  of  the  Alpine  country  and  the  irrigated  fields  of 
the  valley  farmers. 

Antabamba  itself  lies  on  a  smooth,  high-level  shoulder  of  the 
youthful  Antabamba  Valley.  The  valley  floor  is  narrow  and  rocky, 
and  affords  little  cultivable  land.  On  the  valley  sides  are  steep 
descents  and  narrow  benches,  chiefly  structural  in  origin,  over 
w^hich  there  is  scattered  a  growth  of  scrub,  sufficient  to  screen  the 
deer  and  the  bear,  and,  more  rarely,  vagrant  bands  of  vicuiia  that 
stray  down  from  their  accustomed  haunts  in  the  lofty  Cordillera. 
Three  thousand  feet  above  the  valley  floor  a  broad  shoulder  be- 
gins (Fig.  60)  and  slopes  gently  up  to  the  bases  of  the  true  moun- 
tains that  surmount  the  broad  rolling  summit  platform.  Here  are 
the  great  pasture  lands  of  the  Andes  and  their  semi-nomadic  shep- 
herds. The  highest  habitation  in  the  world  is  located  here  at 
17,100  feet  (5,210  m.),  near  a  secondary  pass  only  a  few  miles 
from  the  main  axis  of  the  western  chain,  and  but  300  feet  (91  m.) 
below  it. 

The  people  of  Antabamba  are  both  shepherds  and  farmers. 
The  elevation  is  12,000  feet  (3,658  m.),  too  high  and  exposed  for 
anything  more  lli;iii  potatoes.  Hero  is  an  Indian  i)()])nhili()ii  i)ure- 
blooded,  and  in  other  respects,  too,  but  littk^  altered  from  its 
original  condilioTi.  Tlioro  is  almost  no  communication  with  the 
outside  world.  A  deep  caiiyoii  fi-onts  the  town  and  a  lofty  moun- 
tain range  forms  the  background. 

At  nightfall,  mic  after  .-motlKT.  Ilw  iTuliniis  caiiio  in  fi-oiu  the 
fuld  .'ind  doffed  llieir  e;i})K  as  tlic'V  ]);issod  our  door.  Finally  came 
the  **Teniento  (lobernador,"  or  Lieutenant  Governor.  He  had 
onlv  ;i   sliLdit   strriin   of  white  blood.     His  bonring  was  that    of  a 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER        97 

sneak,  and  he  confirmed  this  impression  by  his  frank  disdain  for 
his  full-blooded  townsmen.  "How  ragged  and  ugly  they  are! 
You  people  must  find  them  very  stupid,"  etc.  When  he  found  that 
we  had  little  interest  in  his  remarks,  he  asked  us  if  we  had  ever 
seen  Lima.  We  replied  that  we  had,  whereupon  he  said,  ' '  Do  you 
see  the  gilded  cross  above  the  church  yonder?  I  brought  that  on 
muleback  all  the  way  from  Lima!  Think  of  it!  These  ignorant 
people  have  never  seen  Lima!"  His  whole  manner  as  he  drew 
himself  up  and  hit  his  breast  was  intended  to  make  us  think  that 
he  was  vastly  superior  to  his  neighbors.  The  sequel  shows  that 
our  first  estimate  of  him  was  correct. 

We  made  our  arrangements  with  the  Governor  and  departed. 
To  inspire  confidence,  and  at  the  Governor's  urgent  request,  we 
had  paid  in  advance  for  our  four  Indians  and  our  fresh  beasts — 
and  at  double  the  usual  rates,  for  it  was  still  winter  in  the 
Cordillera.  They  were  to  stay  with  us  until  we  reached  Cota- 
huasi,  in  the  next  Department  beyond  the  continental  divide, 
where  a  fresh  outfit  could  be  secured.  The  Lieutenant  Governor 
accompanied  us  to  keep  the  party  together.  They  appeared  to 
need  it.  Like  our  Indian  peons  at  Lambrama  the  week  before, 
these  had  been  taken  from  the  village  jail  and  represented  the 
scum  of  the  town.  As  usual  they  behaved  well  the  first  day.  On  the 
second  night  we  reached  the  Alpine  country  where  the  vegetation 
is  very  scanty  and  camped  at  the  only  spot  that  offered  fuel  and 
water.  The  elevation  was  16,000,  and  here  we  had  the  lowest  tem- 
perature of  the  whole  journey,  +  6°  F.  (—14.4°  C).  Ice  covered 
the  brook  near  camp  as  soon  as  the  sun  went  down  and  all  night 
long  the  wind  blew  down  from  the  lofty  Cordillera  above  us,  bring- 
ing flurries  of  snow  and  tormenting  our  unprotected  beasts.  It 
seemed  to  me  doubtful  if  our  Indians  would  remain.  I  discussed 
with  the  other  members  of  the  party  the  desirability  of  chaining 
the  peons  to  the  tent  pole,  but  this  appeared  so  extreme  a  measure 
that  we  abandoned  the  idea  after  warning  the  Teniente  that  he 
must  not  let  them  escape. 

At  daybreak  I  was  alarmed  at  the  unusual  stillness  about 
camp.     A    glance    showed    that    half    our    hobbled    beasts    had 


98  THE  ANDES  OF  SOUTHERN  PERU 

drifted  back  toward  Antabamba  and  no  doubt  were  now  miles 
away.  The  four  Indian  peons  had  left  also,  and  their  tracks, 
half  buried  by  the  last  snowfall,  showed  that  they  had  left 
hours  before  and  that  it  was  useless  to  try  to  overtake  them. 
Furthermore  we  were  making  a  topographic  map  across  the 
Cordillera,  and,  in  view  of  the  likelihood  of  snow  blockading 
the  17,600-foot  (5,360  m.)  pass  which  we  had  to  cross,  the  work 
ought  not  to  be  delayed.  With  all  these  disturbing  conditions  to 
meet,  and  suffering  acutely  from  mountain  sickness,  I  could 
scarcely  be  expected  to  deal  gently  with  our  official.  I  drew  out 
the  sleeping  Teniente  and  set  him  on  his  feet.  To  my  inquiry 
as  to  the  whereabouts  of  the  Indians  that  he  had  promised  to 
guard,  he  blinked  uncertainly,  and  after  a  stupid  "Quien  sabe?" 
peered  under  the  cover  of  a  sheepskin  near  by  as  if  the  peons  had 
been  transformed  into  insects  and  had  taken  refuge  under  a  blade 
of  grass.  I  ordered  him  to  get  breakfast  and  after  that  to  take 
upon  his  back  the  instruments  that  two  men  had  carried  up  to 
that  time,  and  accompany  the  topographer.  Thus  loaded,  the 
Lieutenant  Governor  of  Antabamba  set  out  on  foot  a  little  ahead 
of  the  party.  Ilendriksen,  the  topographer,  directed  him  to  a 
17,000-foot  peak  near  camp,  one  of  the  highest  stations  occupied  in 
the  traverse.  When  the  topographer  reached  the  summit  the  in- 
struments were  there  but  the  Teniente  had  fled.  Hendrikscn  rap- 
idly followed  the  tracks  down  over  the  steep  snow-covered  wall  of 
a  deeply  recessed  cirque,  but  after  a  half-hour's  search  could  not 
get  sight  of  tlie  I'lniaway,  whereupon  he  returned  to  his  station 
and  took  his  observations,  reaching  camp  in  tlio  early  afternoon. 
In  the  meantime  T  had  intercepted  two  Indians  who  had  come 
from  Colahuasi  di-iving  a  llama  train  loaded  with  corn.  They  held 
a  long  conversation  at  the  top  of  the  pass  above  camp  and  at  first 
edged  suspiciously  away,  l^nt  the  rough  ground  turned  them 
back  into  the  frjiil  and  a1  last  llicy  came  timidly  nloiiK.  '^Plicy  pre- 
tended not  1o  nn(l<'i-st;iii(l  Spanish  and  protested  vigorously  that 
they  had  to  keep  on  willi  llicir  llamas.  I  thought  from  ihc  bel- 
ligerent attitude  of  the  older,  which  grew  rapidly  more  threaten- 
ing as  he  saw  that  I  was  alone,  that  I  was  in  for  trouble,  but  when 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER   99 

I  drew  my  revolver  he  quickly  otfeyed  the  order  to  sit  down  to 
breakfast,  which  consisted  of  soup,  meat,  and  army  biscuits.  I 
also  gave  them  coca  and  cigarettes,  the  two  most  desirable  gifts 
one  can  make  to  a  plateau  Indian,  and  thereupon  I  thought  I  had 
gained  their  friendship,  for  they  at  last  talked  with  me  in  broken 
Spanish.  The  older  one  now  explained  that  he  must  at  all  hazards 
reach  Matara  by  nightfall,  but  he  would  be  glad  to  leave  his  son 
to  help  us.  I  agreed,  and  he  set  out  forthmth.  The  arriero 
(muleteer)  had  now  returned  with  the  lost  mules  and  with  the  as- 
sistance of  the  Indian  we  soon  struck  camp  and  loaded  our  mules. 
I  cautioned  the  arriero  to  keep  close  watch  of  the  Indian,  for  at 
one  time  I  had  caught  on  his  face  an  expression  of  hatred  more  in- 
tense than  I  had  ever  seen  before.  The  plateau  Indian  of  South 
America  is  usually  so  stupid  and  docile  that  the  unexpectedly 
venomous  look  of  the  man  after  our  friendly  conversation  and  my 
good  treatment  alarmed  me.  At  the  last  moment,  and  when  our 
backs  were  turned,  our  Indian,  under  the  screen  of  the  packs, 
slipped  away  from  us.  The  arriero  called  out  to  know  where  he 
had  gone.  It  took  us  but  a  few  moments  to  gain  the  top  of  a  hill 
that  commanded  the  valley.  Fully  a  half-mile  away  and  almost 
indistinguishable  against  the  brown  of  the  valley  floor  was  our 
late  assistant,  running  like  a  deer.  No  mule  could  follow  over  that 
broken  ground  at  an  elevation  of  16,000  feet,  and  so  he  escaped. 

Fortunately  that  afternoon  we  passed  a  half-grow^n  boy  riding 
back  toward  Antabamba  and  he  promised  to  hand  the  Governor 
a  note  in  Spanish,  penciled  on  a  leaf  of  my  traverse  book.  I 
dropped  all  the  polite  phrases  that  are  usually  employed  and  wrote 
as  follows : 

"  Senor  Gobernador : 

"  Your  Indians  have  escaped,  likewise  the  Lieutenant  Governor.  They  have 
taken  two  beasts.  In  the  name  of  the  Prefect  of  Abancay,  I  ask  you  immediately 
to  bring  a  fresh  supply  of  men  and  animals.  We  shall  encamp  near  the  first  pass, 
three  days  west  of  Antabamba,  until  you  come." 

We  were  now  without  Indians  to  carry  the  instruments,  which 
had  therefore  to  be  strapped  to  the  mules.  Without  guides  we 
started  w^estward  along  the  trail.     At  the  next  pass  the  topog- 


100  THE  ANDES  OF  SOUTHERN  PERU 

rapher  rode  to  the  summit  of  d  bluff  and  asked  which  of  the  two 
trails  I  intended  to  follow.  Just  then  a  solitary  Indian  passed 
and  I  shouted  back  that  I  would  engage  the  Indian  and  precede 
the  party,  and  he  could  tell  from  my  course  at  the  fork  of  the 
trail  how  to  direct  his  map  and  where  to  gain  camp  at  nightfall. 
But  the  Indian  refused  to  go  with  us.  All  my  threatening  was 
useless  and  I  had  to  force  myself  to  beat  him  into  submission  with 
my  quirt.  Several  repetitions  on  the  way,  when  he  stubbornly  re- 
fused to  go  further,  kept  our  guide  with  us  until  we  reached  a 
camp  site.  I  had  otfered  him  a  week's  pay  for  two  hours'  work, 
and  had  put  coca  and  cigarettes  into  his  hands.  When  these 
failed  I  had  to  resort  to  force.  Now  that  he  was  about  to  leave  I 
gave  him  double  the  amount  I  had  promised  him.  He  could 
scarcely  believe  his  eyes.  He  rushed  up  to  the  side  of  my  mule, 
and  reaching  around  my  waist  embraced  me  and  thanked  me 
again  and  again.  The  plateau  Indian  is  so  often  waylaid  in  the 
mountains  and  impressed  for  service,  then  turned  loose  without 
pay  or  actually  robbed,  that  a  promise  to  pay  holds  no  attraction 
for  him.  I  liad  up  to  the  last  moment  resembled  this  class  of 
white.  He  was  astonished  to  find  that  I  really  meant  to  pay  him 
well. 

Then  he  set  out  upon  the  return,  faithfully  delivering  my  note 
to  the  topographer  about  the  course  of  the  trail  and  the  position 
of  the  camp.  He  had  twelve  miles  to  go  to  the  first  mountain  hut, 
80  that  he  could  not  have  traveled  less  than  that  distance  to  reach 
shelter.  The  next  morning  a  mantle  of  snow  covered  everything, 
yet  when  I  pushed  back  the  tent  flap  there  stood  my  scantily  clad 
Indian  of  the  night  before,  shivering,  with  sandaled  feet  in  the 
snow,  saying  that  he  had  come  back  to  work  for  me ! 

This  camp  was  number  thirteen  out  of  Abancay,  and  here  our 
topograj)lH-i-  was  laid  up  for  three  days.  TTeretoforo  the  elex-ation 
had  had  uo  rfTcct  upon  liiui,  l)ut  the  excessively  lofty  stations  of 
the  past  few  days  and  the  Jiard  elimbing  had  finally  prostrated 
him.  We  liad  deeided  lo  carry  him  out  by  the  fourth  day  if  he 
felt  no  better,  hut  iiaj)|)i]y  he  recovered  sufTiciently  to  continue  the 
work.    The  delay  enabled  the  Governor  to  overtake  us  with  a  fresh 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER      101 

outfit.  On  the  morning  of  our  third  day  in  camp  he  overtook  us 
with  a  small  escort  of  soldiers  accompanied  by  the  fugitive 
Teniente.  He  said  that  he  had  come  to  arrest  me  on  the  charge  of 
maltreating  an  official  of  Peru.  A  few  packages  of  cigarettes  and 
a  handful  of  raisins  and  biscuits  so  stirred  his  gratitude  that  we 
parted  the  best  of  friends.  Moreover  he  provided  us  with  four 
fresh  beasts  and  four  new  men,  and  thus  equipped  we  set  out  for 
a  rendezvous  about  ten  miles  away.  But  the  faithless  Governor 
turned  off  the  trail  and  sought  shelter  at  the  huts  of  a  company 
of  mountain  shepherds.  That  night  his  men  slept  on  the  ground 
in  a  bitter  wind  just  outside  our  camp  at  17,200  feet.  They  com- 
plained that  they  had  no  food.  The  Governor  had  promised  to 
join  us  with  llama  meat  for  the  peons.  We  fed  them  that  night 
and  also  the  next  day.  But  we  had  by  that  time  passed  the  crest 
of  the  western  Cordillera  and  were  outside  the  province  of  Anta- 
bamba.  The  next  morning  not  only  our  four  men  but  also  our 
four  beasts  were  missing.  We  were  stranded  and  sick  just  under 
the  pass.  To  add  to  our  distress  the  surgeon,  Dr.  Erving,  was 
obliged  to  leave  us  for  the  return  home,  taking  the  best  saddle 
animal  and  the  strongest  pack  mule.  It  was  impossible  to  go  on 
with  the  map.  That  morning  I  rode  alone  up  a  side  valley  until 
I  reached  a  shepherd 's  hut,  where  I  could  find  only  a  broken-down, 
shuffling  old  mule,  perfectly  useless  for  our  hard  work. 

Then  there  happened  a  piece  of  good  luck  that  seems  almost 
providential.  A  young  man  came  down  the  trail  with  three  pack 
mules  loaded  with  llama  meat.  He  had  come  from  the  Cotahuasi 
Valley  the  week  before  and  knew  the  trail.  I  persuaded  him  to 
let  us  hire  one  of  his  mules.  In  this  way  and  by  leaving  the  in- 
struments and  part  of  our  gear  in  the  care  of  two  Indian  youths 
we  managed  to  get  to  Cotahuasi  for  rest  and  a  new  outfit. 

The  young  men  who  took  charge  of  part  of  our  outfit  interested 
me  very  greatly.  I  had  never  seen  elsewhere  so  independent  and 
clear-eyed  a  pair  of  mountain  Indians.  At  first  they  would  have 
nothing  to  do  with  us.  They  refused  us  permission  to  store  our 
goods  in  their  hut.  To  them  we  were  railroad  engineers.  They 
said  that  the  railway  might  come  and  when  it  did  it  would  depopu- 


102  THE  ANDES  OF  SOUTHERN  PERU 

late  the  country.  The  railway  was  a  curse.  Natives  were  obliged 
to  work  for  the  company  without  pay.  Their  uncle  had  told  them 
of  frightful  abuses  over  at  Cuzco  and  had  warned  them  not  to 
help  the  railway  people  in  any  way.  They  had  moved  out  here 
in  a  remote  part  of  the  mountains  so  that  white  men  could  not 
exploit  them. 

In  the  end,  however,  we  got  them  to  understand  the  nature  of 
our  work.  Gifts  of  various  sorts  won  their  friendship,  and  they 
consented  to  guard  the  boxes  we  had  to  leave  behind.  Two  weeks 
later,  on  his  return,  the  topographer  found  everything  unmolested. 

I  could  not  but  feel  that  the  spirit  of  those  strong  and  inde- 
pendent young  men  was  much  better  for  Peru  than  the  cringing, 
subservient  spirit  of  most  of  the  Indians  that  are  serfs  of  the 
whites.  The  policy  of  the  w^hites  has  been  to  suppress  and  ex- 
ploit the  natives,  to  abuse  them,  and  to  break  their  spirit.  They 
say  that  it  keeps  down  revolution;  it  keeps  the  Indian  in  his  place. 
But  certainly  in  other  respects  it  is  bad  for  the  Indian  and  it  is 
worse  for  the  whites.  Their  brutality  toward  the  natives  is  in- 
credible. It  is  not  so  much  the  white  himself  as  the  vicious  half- 
breed  who  is  often  allied  with  him  as  his  agent. 

I  shall  never  forget  the  terror  of  two  young  girls  driving  a  don- 
key before  them  when  they  came  suddenly  face  to  face  with  our 
party,  and  we  at  the  same  time  hastily  scrambled  off  our  beasts 
to  get  a  photograph  of  a  magnificent  view  disclosed  at  the  bend 
of  the  steep  trail.  They  thought  we  had  dismounted  to  attack 
them,  and  fled  screaming  in  abject  fear  up  the  mountain  side, 
abandoning  1Ik'  (lonlcey  and  the  pack  of  potatoes  which  must  have 
represented  a  hirge  part  of  the  season's  product.  It  is  a  kind  of 
highway  robbery  condoned  because  it  is  only  robbing  an  Indian. 
Tie  is  considered  to  l)e  lawful  prey.  His  complaint  goes  unnoticed. 
In  llio  past  a  rovolntion  lias  offered  him  sporadic  chances  to  wreak 
vengoanr'e.  More  often  it  adds  to  his  troubles  by  scattering 
IhronLrl)  the  niountaiii  valleys  the  desperate  refugees  or  lawless 
bands  of  marauders  who  kill  the  floeks  of  tlu^  nioiintain  shepherds 
and  despoil  their  women. 

There  are  still  considerable  nnni])ers  of  Indians  wlio  shun  the 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER      103 

white  man  and  live  in  the  most  remote  corners  of  the  mountains. 
I  have  now  and  again  come  upon  the  most  isolated  huts,  invisible 
from  the  valley  trails.  They  were  thatched  with  grass ;  the  walls 
were  of  stone;  the  rafters  though  light  must  have  required  pro- 
digious toil,  for  all  timber  stops  at  12,000  feet  on  the  mountain 
borders.  The  shy  fugitive  who  perches  his  hut  near  the  lip  of  a 
hanging  valley  far  above  the  trail  may  look  down  himself  unseen 
as  an  eagle  from  its  nest.  When  the  owner  leaves  on  a  journey, 
or  to  take  his  flock  to  new  pastures,  he  buries  his  pottery  or  hides 
it  in  almost  inaccessible  caves.  He  locks  the  door  or  bars  it,  thank- 
ful if  the  spoiler  spares  rafters  and  thatch. 

At  length  we  reached  Cotahuasi,  a  town  sprawled  out  on  a  ter- 
race just  above  the  floor  of  a  deep  canyon  (Fig.  29) .  Its  flower  gar- 
dens and  pastures  are  watered  by  a  multitude  of  branching  canals 
lined  with  low  willows.  Its  bright  fields  stretch  up  the  lower 
slopes  and  alluvial  fans  of  the  canyon  to  the  limits  of  irrigation 
where  the  desert  begins.  The  fame  of  this  charming  oasis  is  wide- 
spread. The  people  of  Antabamba  and  Lambrama  and  even  the 
officials  of  Abancay  spoke  of  Cotahuasi  as  practically  the  end  of 
our  journey.  Fruits  ripen  and  flowers  blossom  every  month 
of  the  year.  Where  we  first  reached  the  canyon  floor  near 
Huaynacotas,  elevation  11,500  feet  (3,500  m.),  there  seemed  to  be 
acres  of  rose  bushes.  Only  the  day  before  at  an  elevation  of 
16,800  feet  (5,120  m.)  we  had  broken  thick  ice  out  of  a  mountain 
spring  in  order  to  get  water ;  now  we  were  wading  a  shallow  river, 
and  grateful  for  the  shade  along  its  banks.  Thus  we  came  to  the 
town  prepared  to  find  the  people  far  above  their  plateau  neigh- 
bors in  character.  Yet,  in  spite  of  friendly  priests  and  officials 
and  courteous  shopkeepers,  there  was  a  spirit  strangely  out  of 
harmony  with  the  pleasant  landscape. 

Inquiries  showed  that  even  here,  where  it  seemed  that  only 
sylvan  peace  should  reign,  there  had  recently  been  let  loose  the 
spirit  of  barbarism.  We  shall  turn  to  some  of  its  manifestations 
and  look  at  the  reasons  therefor. 

In  the  revolution  of  1911  a  mob  of  drunken,  riotous  citizens 
gathered  to  storm  the  Cotahuasi  barracks  and  the  jail.    A  full- 


101  THE  ANDES  OF  SOUTHERN  PERU 

blooded  Indian  soldier,  on  duty  at  the  entrance,  ordered  the  rioters 
to  stop  and  when  they  paid  no  heed  he  shot  the  leader  and  scat- 
tered the  crowd.  The  captain  thereupon  ordered  the  soldier  to 
Arequipa  because  his  life  was  no  longer  safe  outside  the  barracks. 
A  few  months  later  he  was  assigned  to  Professor  Bingham's 
Coropuna  expedition.  Professor  Bingham  reached  the  Cotahuasi 
Valley  as  I  was  about  to  leave  it  for  the  coast,  and  the  soldier  was 
turned  over  to  me  so  that  he  might  leave  Cotahuasi  at  the  earliest 
possible  moment,  for  his  enemies  were  plotting  to  kill  -him. 

He  did  not  sleep  at  all  the  last  night  of  his  stay  and  had  us 
called  at  three  in  the  morning.  He  told  his  friends  that  he  was 
going  to  leave  with  us,  but  that  they  were  to  announce  his  leav- 
ing a  day  later.  In  addition,  the  Subprefect  was  to  accompany 
us  until  daybreak  so  that  no  harm  might  befall  mo  while  under 
the  protection  of  a  soldier  who  expected  to  be  shot  from  ambush. 

At  four  o'clock  our  whispered  arrangements  were  made,  Ave 
opened  the  gates  noiselessly,  and  our  small  cavalcade  hurried 
through  the  pitch-black  streets  of  the  town.  The  soldier  rode 
ahead,  his  rifle  across  his  saddle,  and  directly  behind  him  rode 
the  Subprefect  and  myself.  The  pack  mules  were  in  the  rear.  We 
had  almost  reached  the  end  of  the  street  when  a  door  opened  sud- 
denly and  a  shower  of  sparks  flew  out  ahead  of  us.  Instantly  the 
soldier  struck  spurs  into  his  mule  and  turned  into  a  side  street. 
The  Subprefect  drew  his  horse  back  savagely  and  when  the  next 
shower  of  sparks  flew  out  pushed  me  against  the  wall  and 
wliispered:  "Poi-  Dios,  quien  es?"  Then  suddenly  he  shouted: 
"S(>i)la  no  mas,  s()j)la  no  mas"  (stop  blowing). 

''I'lHTciipon  a  shab])y  penitent  man  came  to  the  door  holding  in 
liis  IkiihI  a  large  tailor's  flatiron.  The  base  of  it  was  filled  with 
glctwiiiL''  cliaico.-il  iiikI  he  was  a])out  to  stai't  his  day's  work.  The 
sparks  were  m.-idc  in  llic  })rocess  (d"  ])I()\viiig  llirouuli  ilic  ii'on  to 
start  the  smoldering  coals.  We  greeted  liiiii  wiili  more  than 
nrdiiiMry  friendliness  and  passed  on. 

At  daybreak  we  li;id  reiielied  the;  steej)  western  wall  of  the 
canyon  where  the  rc.-d  ascent  begins,  and  here  the  Subprefect 
liiiiieij   b;ick   witii   ninny  fdicidades  for  tlir  journey  and  threats 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER      105 

for  the  soldier  if  he  did  not  look  carefully  after  the  pack  train. 
From  every  angle  of  the  zigzag  trail  that  climbs  the  "cuesta"  the 
soldier  scanned  the  valley  road  and  the  trail  below  him.  He  was 
anxious  lest  news  of  his  escape  reach  his  enemies  who  had  vowed 
to  take  his  life.  Half  the  day  he  rode  turned  in  his  saddle  so  as 
to  see  every  traveler  long  before  he  was  within  harm's  reach.  By 
nightfall  we  safely  reached  Salamanca,  fifty  miles  away  (Fig.  62). 

The  alertness  of  the  soldier  was  unusual  and  I  quite  enjoyed 
his  close  attention  to  the  beasts  and  his  total  abstinence,  for  an 
alert  and  sober  soldier  on  detail  is  a  rare  phenomenon  in  the  in- 
terior of  Peru.  But  all  Salamanca  was  drunk  when  we  arjjyed 
— Governor,  alcaldes^  citizens^  Even  the  peons  drank  up  in  brandy 
the  money  that  we  gave  them  for  forage  and  let  the  beasts  starve. 
The  only  sober  person  I  saw  was  the  white  telegraph  operator 
from  Lima.  He  said  that  he  had  to  stay  sober,  for  the  telegraph 
office — the  outward  sign  of  government — was  the  special  object 
of  attack  of  every  drink-crazed  gang  of  rioters.  They  had  tried 
to  break  in  a  few  nights  before  and  he  had  fired  his  revolver  point- 
blank  through  the  door.  The  town  offered  no  shelter  but  the  dark 
filthy  hut  of  the  Gobernador  and  the  tiny  telegraph  office.  So  I 
made  up  my  bed  beside  that  of  the  operator.  We  shared  our  meals 
and  chatted  until  a  late  hour,  he  recounting  the  glories  of  Lima, 
to  which  he  hoped  to  return  at  the  earliest  possible  moment,  and 
cursing  the  squalid  town  of  Salamanca.  His  operator's  keys  were 
old,  the  batteries  feeble,  and  he  was  in  continual  anxiety  lest  a 
message  could  not  be  received.  In  the  night  he  sprang  out  of  bed 
shouting  frantically : 

"Estan  llamando"  (they  are  calling),  only  to  stumble  over  my 
bed  and  awaken  himself  and  offer  apologies  for  walking  in  his 
sleep. 

Meanwhile  my  soldier,  having  regained  his  courage,  began 
drinking.  It  was  with  great  difficulty  that  I  got  started,  after  a 
day's  delay,  on  the  trail  to  Ohuquibamba.  There  his  thirst  quite 
overcame  him.  To  separate  him  from  temptation  it  became  nec- 
essary to  lock  him  up  in  the  village  jail.  This  I  did  repeatedly  on 
the  way  to  Mollendo,  except  beyond  Quilca,  where  we  slept  in  the 


106  THE  ANDES  OF  SOUTHERN  PERU 

hot  marshy  valley  out  of  reach  of  drink,  and  where  the  mosquitoes 
kept  us  so  busy  that  either  eating  or  drinking  was  almost  out  of 
the  question. 

The  drunken  rioters  of  Cotahuasi  and  their  debauched  brothers 
at  Salamanca  are  chiefly  natives  of  pure  or  nearly  pure  Indian 
blood.  They  are  a  part  of  the  great  plateau  population  of  the 
Peruvian  Andes.  Have  they  degenerated  to  their  present  low 
state,  or  do  they  display  merely  the  normal  condition  of  the 
plateau  people?  Why  are  they  so  troublesome  an  element?  To 
this  as  to  so  many  questions  that  arise  concerning  the  highland 
population  we  find  our  answer  not  chiefly  in  government,  or  re- 
ligion, or  inherited  character,  but  in  geography.  I  doubt  very 
much  if  a  greater  relative  difference  would  be  seen  if  two  groups 
of  whites  were  set  do^\Ti,  the  one  in  the  cold  terrace  lands  of 
Salamanca,  the  other  in  the  warm  vineyards  of  Aplao,  in  the  Majes 
\'alley.  The  common  people  of  these  two  towns  were  originally 
of  the  same  race,  but  the  lower  valley  now  has  a  white  element 
including  even  most  of  those  having  the  rank  of  peons.  Greater 
differences  in  character  could  scarcely  be  found  between  the  Aztecs 
and  the  Iroquois.  In  the  warm  valley  there  is  of  coarse  drunken- 
ness, but  it  is  far  from  general ;  there  is  stupidity,  but  the  people 
are  as  a  whole  alert;  and  finally,  the  climate  and  soil  produce 
grapes  from  which  famous  mnes  are  made,  they  produce  sugar 
cane,  cotton,  and  alfalfa,  so  that  the  whites  have  come  in,  diluted 
the  Indian  blood,  and  raised  the  standard  of  life  and  behavior. 
Undouljfedly  their  influence  would  tend  to  have  the  same  general 
effect  if  they  mixed  in  equal  numbers  with  the  plateau  groups. 
There  is,  however,  a  good  reason  for  their  not  doing  so. 

The  lofty  towns  of  the  plateau  have  a  really  wretched  climate. 
W  liilf  mf-n  cannot  live  comfortably  at  Antabamba  and  Salamanca. 
I''urtli<r,  tlioy  are  so  isolated  that  the  modest  comforts  and  the 
smallest  luxuries  of  ciNiJizafion  are  very  expensive.  To  pay  for 
them  re(|uir(s  a  profilablo  industry  managed  on  a  large  scale  and 
there  is  tio  such  industry  in  the  higher  valleys.  The  white  who 
goes  there  must  ])e  satisfied  to  live  like  an  Indian.  The  result  is 
easy  to  forecast.    Outside  of  government  oflicers,  only  the  disso- 


Fig.  60. 


Fig.   G1. 


Fig.  60 — View  across  the  Aiitabaniba  canyon   just  above  Huadqiiirca. 
Fig.   61 — Huancarama,   west  of   Abancay,   on   the   famous   Lima    to   Buenos   Aires 
road.    Note  the  smooth  slopes  in  the  forej^round.     See  Chapter  XI. 


o 

O    3 


2   g 

::.'^ 


o    , 


<    ^ 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER      107 

lute  or  unsuccessful  whites  live  in  the  worst  towns,  like  Salamanca 
and  Antabamba.  A  larger  valley  with  a  slightly  milder  climate 
and  more  accessible  situation,  like  Chuquibamba,  will  draw  a  still 
better  grade  of  white  citizen  and  in  the  largest  of  all — Cuzco  and 
the  Titicaca  basin — we  find  normal  whites  in  larger  numbers, 
though  they  nowhere  live  in  such  high  ratios  to  the  Indian  as  on 
the  coast  and  in  the  lower  valleys  near  the  coast.  With  few  ex- 
ceptions the  white  population  of  Peru  is  distributed  in  response 
to  favorable  combinations  of  climate,  soil,  accessibility,  and  gen- 
eral opportunities  to  secure  a  living  without  extreme  sacrifice."" -.. 

These  facts  are  stated  in  a  simple  way,  for  I  wish  to  emphasize 
the  statement  that  the  Indian  population  responds  to  quite  other 
stimuli.  Most  of  the  luxuries  and  comforts  of  the  whites  mean 
nothing  to  the  Indian.  The  machine-made  woolens  of  the  im- 
porters will  probably  never  displace  his  homespun  llama-wool  ^ 
clothing.  His  implements  are  few  in  number  and  simple  in  form. 
His  tastes  in  food  are  satisfied  by  the  few  products  of  his  fields  ' 
and  his  mountain  flocks.  Thus  he  has  lived  for  centuries  and  is 
quite  content  to  live  today.  Only  coca  and  brandy  tempt  him  to 
engage  in  commerce,  to  toil  now  and  then  in  the  hot  valleys,  and 
to  strive  for  more  than  the  bare  necessities  of  life.  Therefore 
it  matters  very  little  to  him  if  his  home  town  is  isolated,  or  the 
resources  support  but  a  small  group  of  people.  He  is  so  ac- 
customed to  a  solitary  existence  in  his  ramblings  with  his  flocks 
that  a  village  of  fifty  houses  offers  social  enjoyments  of  a  high 
order.  Where  a  white  perishes  for  lack  of  society  the  Indian  finds 
himself  contented.  Finally,  he  is  not  subject  to  the  white  man's 
exploitation  when  he  lives  in  remote  places.  The  pastures  are  ex- 
tensive and  free.  The  high  valley  lands  are  apportioned  by  the 
alcalde  according  to  ancient  custom.  His  life  is  unrestricted  by 
anything  but  the  common  law  and  he  need  have  no  care  for  the 
morrow,  for  the  seasons  here  are  almost  as  fixed  as  the  stars.      / 

Thus  we  have  a  sort  of  segregation  of  whites  in  the  lower 
places  where  a  modern  type  of  life  is  maintained  and  of  Indians 
in  the  higher  places  where  they  enjoy  advantages  that  do  not  ap- 
peal to  the  whites.    Above  8,000  feet  the  density  of  the  white  popu- 


108  THE  ANDES  OF  SOUTHERN  PERU 

latiou  bears  a  close  inverse  proportion  to  the  altitude,  excepting 
in  the  case  of  the  largest  valleys  whose  size  brings  together  such 
numbers  as  to  tempt  the  conmiercial  and  exploiting  whites  to  live 
in  them.  Furthermore,  we  should  find  that  high  altitude,  limited 
size,  and  greater  isolation  are  everywhere  closely  related  to  in- 
creasing immorality  or  decreasing  character  among  the  whites.  So 
to  the  low  Indian  population  there  is  thus  added  the  lowest  of  the 
white  population.  Moreover,  because  it  yields  the  largest  returns, 
the  chief  business  of  these  whites  is  the  sale  of  coca  and  brandy 
and  the  downright  active  debauchery  of  the  Indian.  This  is  all 
the  easier  for  them  because  the  isolated  Indian,  like  the  average 
isolated  white,  has  only  a  low  and  provincial  standard  of  morality 
and  gets  no  help  from  such  stimulation  as  numbers  usually  excite. 

For  example,  the  Anta  basin  at  harvest  time  is  one  of  the  fair- 
est sights  in  Peru.  Sturdy  laborers  are  working  diligently.  Their 
faces  are  bright  and  happy,  their  skin  clear,  their  manner  eager 
and  animated.  They  sing  at  their  work  or  gather  about  their  mild 
chicha  and  drink  to  the  patron  saints  of  the  harvest.  The  huts  are 
filled  with  robust  children ;  all  the  yards  are  turned  into  threshing 
floors;  and  from  tlie  stubbly  hillslopes  the  shepherd  blows  shrill 
notes  upon  his  barley  reeds  and  bamboo  flute.  There  is  drinking 
but  there  is  little  disorder  and  there  is  always  a  sober  remnant 
that  exercises  a  restraining  influence  upon  the  group. 

In  the  most  remote  places  of  all  one  may  find  mountain  groups 
of  a  high  order  of  morality  unaffected  by  the  white  man  or  actu- 
ally shunning  him.  Clear-eyed,  thick-limbed,  independent,  a  fine, 
sturdy  type  of  man  this  highland  shepherd  may  be.  But  in  the 
town  lio  succumbs  to  the  temptation  of  drink.  Some  writers  have 
tried  to  make  liim  out  a  superior  to  the  plains  and  low  valley  type. 
Ho  is  not  that.  The  well-regulated  groups  of  the  lower  elevations 
ni-f  far  superior  inlcllcclnnlly  and  morally  in  spite  of  the  fact  that 
tho  poorly  regulated  groups  may  fall  below  the  highland  dweller 
in  nior.'ility.  Tlic  coca-chewing  highlander  is  a  clod.  Surely,  as 
a  wliolc,  till'  mixed  breed  of  the  coastal  valleys  is  a  far  worthier 
typo,  save  in  a  few  cases  whore  a  ('iiinesc  or  negroid  element  or 
both  have  led  to  local  inferiority.    And  surely,  also,  that  is  the 


THE  GEOGRAPHIC  BASIS  OF  HUMAN  CHARACTER      109 

worst  combination  which  results  in  adding  the  viciousness  of  the 
inferior  or  debased  white  to  the  stupidity  of  the  highland  Indian. 
It  is  here  that  the  effects  of  geography  are  most  apparent.  If  the 
white  is  tempted  in  large  numbers  because  of  exceptional  position 
or  resources,  as  at  La  Paz,  the  rule  of  altitude  may  have  an  excep- 
tion. And  other  exceptions  there  are  not  due  to  physical  causes, 
for  character  is  practically  never  a  question  of  geography  alone. 
There  is  the  spiritual  factor  that  may  illumine  a  strong  character 
and  through  his  agency  turn  a  weak  community  into  a  powerful 
one,  or  hold  a  weakened  group  steadfast  against  the  forces  of  dis- 
integration. Exceptions  arise  from  this  and  other  causes  and  yet 
Avith  them  all  in  mind  the  geographic  factor  seems  predominant  in 
the  tj^es  illustrated  here^^dth.^ 


^  During  his  travels  Raimondi  collected  many  instances  of  the  isolation  and  con- 
servatism of  the  plateau  Indian:  thus  there  is  the  village  of  Pampacolca  near  Coro- 
puna,  whose  inhabitants  until  recently  carried  their  idols  of  clay  to  the  slopes  of  the 
great  white  mountain  and  worshiped  them  there  with  the  ritual  of  Inca  days  (El  Peru, 
Lima,  1874,  Vol.  1). 


CHAPTER  VIII 

THE  COASTAL  DESERT 

/  To  the  wayfarer  from  the  bleak  mountains  the  warm  green  val- 
leys of  the  coastal  desert  of  Peru  seem  like  the  climax  of  scenic 
beauty.  The  streams  are  intrenched  from  2,000  to  4,000  feet,  and 
the  valley  walls  in  some  places  drop  500  feet  by  sheer  descents 
from  one  level  to  another.  The  cultivated  fields  on  the  valley 
floors  look  like  sunken  gardens  and  now  and  then  one  may  catch 
the  distant  glint  of  sunlight  on  water.  The  broad  white  path  that 
winds  through  vineyards  and  cotton-fields,  follows  the  foot  of  a 
cliff,  or  fills  the  whole  breadth  of  a  gorge  is  the  waste-strewn, 
half-dry  chamiel  of  the  river.  In  some  places  almost  the  whole  floor 
is  cultivated  from  one  valley  wall  to  the  other.  In  other  places 
the  fields  are  restricted  to  narrow  bands  between  the  river  and  the 
impending  cliffs  of  a  narrow  canyon.  Where  tributaries  enter 
from  the  desert  there  may  be  huge  banks  of  mud  or  broad  triangu- 
lar fans  covered  with  raw,  infertile  earth.  The  picture  is  gener- 
ally touched  with  color — a  yellow,  haze-covered  horizon  on  the  bare 
desert  above,  brown  lava  flows  suspended  on  the  brink  of  the  val- 
ley, gray-brown  cliffs,  and  greens  ranging  from  the  dull  shade  of 
algarrobo,  olive  and  fig  trees,  to  the  bright  shade  of  freshly  irri- 
gated alfalfa  pastures. 

After  several  months'  work  on  the  cold  highlands,  whore  we 
rode  almost  daily  into  hailstorms  or  wearisome  gales,  we  came  at 
length  to  the  border  of  the  valley  country.  It  will  always  seem  to 
mo  that  the  weather  and  the  sky  conspired  that  afternoon  to  re- 
ward UH  for  the  months  of  toil  that  lay  behind.  And  certainly 
there  could  be  no  happier  place  to  receive  the  reward  than  on  the 
brink  of  the  lava  plateau  above  Chuquibamba.  There  was  prom- 
ise of  an  extraordinary  view  in  tlie  growing  beauty  of  the  sky, 
and  we  hurried  our  tired  beasts  forward  so  that  the  valley  below 

no 


Fig.   63. 


Fig.   04. 


Fig.  63— The  deep  fertile  Majes  Valley  below  Caiitas.  Compare  with  Fig.  6  show- 
ing the  Chili  Valley  at  Arequipa. 

Fig.  64— The  Majes  Valley,  desert  coast,  western  Peru.  The  lighter  patches  on  the 
valley  floor  are  the  gravel  beds  of  the  river  at  high  water.  Much  of  the  alluvial  land 
is  still  uncleared. 


THE  COASTAL  DESERT  111 

might  also  be  included  in  the  picture.  The  head  of  the  Majes  Val- 
ley is  a  vast  hollow  bordered  by  cliffs  hundreds  of  feet  high,  and 
we  reached  the  rim  of  it  only  a  few  minutes  before  sunset. 

I  remember  that  we  halted  beside  a  great  wooden  cross  and 
that  our  guide,  dismounting,  walked  up  to  the  foot  of  it  and  kissed 
and  embraced  it  after  the  custom  of  the  mountain  folk  when  they 
reach  the  head  of  a  steep  ''cuesta."  Also  that  the  trail  seemed 
to  drop  off  like  a  stairway,  which  indeed  it  was.^  Everything  else 
about  me  was  completely  overshadowed  by  snowy  mountains,  col- 
ored sky,  and  golden-yellow  desert.  One  could  almost  forget  the 
dark  clouds  that  gather  around  the  great  mass  of  Coropuna  and 
the  bitter  winds  that  creep  down  from  its  glaciers  at  night — it 
seemed  so  friendly  and  noble.  Behind  it  lay  bulky  masses  of  rose- 
tinted  clouds.  We  had  admired  their  gay  colors  only  a  few  min- 
utes, when  the  sun  dropped  behind  the  crest  of  the  Coast  Range 
and  the  last  of  the  sunlight  played  upon  the  sky.  It  fell  with  such 
marvelously  swift  changes  of  color  upon  the  outermost  zone  of 
clouds  as  these  were  shifted  with  the  wind  that  the  eye  had 
scarcely  time  to  comprehend  a  tint  before  it  was  gone  and  one 
more  beautiful  still  had  taken  its  place.  The  reflected  sunlight 
lay  warm  and  soft  upon  the  white  peaks  of  Coropuna,  and  a  little 
later  the  Alpine  glow  came  out  delicately  clear. 

When  we  turned  from  this  brilliant  scene  to  the  deep  valley, 
we  found  that  it  had  already  become  so  dark  that  its  greens  had 
turned  to  black,  and  the  valley  walls,  now  in  deep  shadow,  had  lost 
half  their  splendor.  The  color  had  not  left  the  sky  before  the 
lights  of  Chuquibamba  began  to  show,  and  candles  twinkled  from 
the  doors  of  a  group  of  huts  close  under  the  cliff.  We  were  not 
long  in  starting  the  descent.  Here  at  last  were  friendly  habita- 
tions and  happy  people.  I  had  worked  for  six  weeks  between 
12,000  and  17,000  feet,  constantly  ill  from  mountain  sickness,  and 
it  was  with  no  regret  that  I  at  last  left  the  plateau  and  got  down 

^  Raimondi  (op.  cit.,  p.  109)  has  a  characteristic  description  of  the  "  Camino  del 
Penon  "  in  the  department  of  La  -Libertad :  " .  .  .  the  ground  seems  to  disappear  from 
one's  feet;  one  is  standing  on  an  elevated  balcony  looking  down  more  than  6,000  feet 
to  the  valley  .    .    .   the  road  which  descends  the  steep  scarp  is  a  masterpiece." 


112 


THE  ANDES  OF  SOUTHERN  PERU 


to  comfortable  altitudes.  It  seemed  good  news  when  the  guide 
told  me  that  there  were  mosquitoes  in  the  marshes  of  Camana. 
Any  low,  hot  land  would  have  seemed  like  a  health  resort.  I  had 
been  in  the  high  country  so  long  that,  like  the  Bolivian  mining- 
engineer,  I  wanted  to  get  do\\Ti  not  only  to  sea  level,  but  below  it ! 
If  the  reader  will  examine  Figs.  65  and  66,  and  the  photographs 
that  accompany  them,  he  may  gain  an  idea  of  the  more  important 


Fig.   65 — Regional  diagram  to  show  the  physical  relations  in  the  coastal  desert 
of  IVrii.     For  location,  see  Fig.  20. 

features  of  tlic  coastal  region.  We  have  already  described,  in 
Chapters  \'  ;iii<l  VII,  the  character  of  the  plateau  region  and  its 
people.  Therefore,  we  need  say  little  in  this  place  of  the  part 
of  the  Maritime  Cordillera  that  is  included  in  the  figure.  Its 
uiii)<)pulato(l  rim  (see  p.  54),  the  semi-nomadic  Jierdsmen  and  shep- 
herds from  { TuKiuibamba  that  scour  its  pastures  in  the  moist 
vales  about  Coropuna,  and  the  gnarled  and  stunted  trees  at  13,000 
feet  (3,9(50  m.)  wltidi  partly  sujjply  Chuquibamba  with  firewood, 
ar<'  its  most  impoj-taiil  features.  A  few  groui)s  of  huts  just  uuder 
the  siiowjiiic  ;irc  iiilwihilcd  fof  only  a  i)art  of  the  year.  The  de- 
lightful Nalh'vs  arc  loo  near  and  Icmpting,  Even  a.  ])lateau 
Indian  responds  U)  liic  call  of  a  dry  valley,  however  he  may  shun 
the  moist,  warm  valleys  on  the  eastern  border  of  the  Cordillera. 


THE  COASTAL  DESERT 


113 


LEGEND 

Irrigated  Land 
IrrUjnUe     „ 
Desert  pliiiiis 

Limit  hctm'rn  mountain  zone  of 
onmuil  rains  and  coastdl  zone  of 
ruins  at  intrnals  of  se\craL years 
Crest  of  Maritime  Cordillera  or 
"Cordillera  Occidental  " 


Fig.  66 — Irrigated  and  irrigable  land  of  the  coastal  belt  of  Peru.  The  map  ex- 
hibits in  a  striking  manner  how  small  a  part  of  the  whole  Pacific  slope  is  available  for 
cultivation.  Pasture  grows  over  all  but  the  steepest  and  th^  highest  portions  of  the 
Cordillera  to  the  right  of  (above)  the  dotted  line.'  Another  belt  of  pasture  too  nar- 
row to  show  on  the  map,  grows  in  the  fog  belt  on  the  seaward  slopes  of  the  Coast 
Range.    Scale,  170  miles  to  the  inch. 


lU  THE  ANDES  OF  SOUTHERN  PERU 

The  greater  part  of  the  coastal  region  is  occupied  by  the  des- 
ert. Its  outer  border  is  the  low,  dry,  gentle,  eastward-facing  slope 
of  the  Coast  Eange.  Its  inner  border  is  the  foot  of  the  steep 
descent  that  marks  the  edge  of  the  lava  plateau.  This  descent  is 
a  fairly  well-marked  line,  here  and  there  broken  by  a  venturesome 
lava  flow  that  extends  far  out  from  the  main  plateau.  Within 
these  definite  borders  the  desert  extends  continuously  northwest- 
ward for  hundreds  of  miles  along  the  coast  of  Peru  from  far  be- 
yond the  Chilean  frontier  almost  to  the  border  of  Ecuador.  It  is 
broken  up  by  deep  tranverse  valleys  and  canyons  into  soTcalled 
''pampas,"  each  of  which  has  a  separate  name;  thus  west  of 
Arequipa  between  the  Vitor  and  Majes  valleys  are  the  "Pampa 
de  Vitor"  and  the  "Pampa  de  Sihuas,"  and  south  of  the  Vitor 
is  the  ''Pampa  de  Islay." 

The  pampa  surfaces  are  inclined  in  general  toward  the  sea. 
They  were  built  up  to  their  present  level  chiefly  by  mountain 
streams  before  the  present  deep  valleys  were  cut,  that  is  to  say, 
when  the  land  was  more  than  a  half-mile  lower.  Some  of  their 
material  is  wind-blown  and  on  the  walls  of  the  valleys  are  alter- 
nating belts  of  wind-blown  and  water-laid  strata  from  one  hun- 
dred to  four  hundred  feet  thick  as  if  in  past  ages  long  dry  and 
long  wet  periods  had  succeeded  each  other.  The  wind  has  blown 
sand  and  dust  from  the  desert  down  into  the  valleys,  but  its  chief 
work  has  been  to  drive  the  lighter  desert  waste  up  partly  into  the 
mountains  and  lilouu;  Ww'w  margins,  partly  so  high  as  to  carry  it" 
into  tlic  realm  of  liic  h)fty  terrestrial  winds,  whence  it  falls  upon 
surfaces  far  distant  from  the  fields  of  origin.  Tliero  are  left 
behind  the  heavier  sand  which  the  wind  rolls  along  on  the  sur- 
/  faces  and  builds  into  crescentic  dunes  called  medanos,  and  the  peb- 
I  hies  that  it  can  sandpaper  but  cannot  remove  bodily.  Thus  there 
are  l)olts  of  (hiiies,  l)el1s  of  irregular  sand  drifts,  and  belts  of  hue 
desert  "[)avement"  (a  residual  mantle  of  faceted  pebbles  and 
irre^-ular  .stones). 

Vet  another  feature  of  the  desert  pampa  are  the  "dry"  val- 
leys that  Join  the  tlirough-flowing  streams  at  irregular  intervals, 
as  shown  in  the  accompanying  regional  diagram.    If  one  follow 


IPJECI 


i6°2i 


'  ±eet . 
I. 


TTTTT-W^ 


^ 


/'       .1        (■       I        /••        /        (■ 

(>      c     /■;      .1       .\- 


(3 


THE  COASTAL  DESERT  115 

a  dry  valley  to  its  head  he  will  find  there  a  set  of  broad  and  shal- 
low tributaries.    Sand  drifts  may  clog  them  and  appear  to  indi- 
cate that  water  no  longer  flows  through  them.    They  are  often  re- 
ferred to  by  unscientific  travelers  as  evidences  of  a  recent  change 
of  climate.    I  had  once  the  unusual  opportunity  (in  the  mountains 
of  Chile)  of  seeing  freshly  fallen  snow  melted  rapidly  and  thus  I 
turned  suddenly  into  the  streams.    In  1911  this  happened  also  at  i 
San  Pedro  de  Atacama,  northern  Chile,  right  in  the  desert  at , 
8,000  feet  (2,440  m.)  elevation,  and  in  both  places  the  dry,  sand-  '"^ 
choked  valleys  were  cleaned  out  and  definite  channels  reestab-    | 
lished.    From  a  large  number  of  facts  like  these  we  know  that  the   ' 
dry  valleys  represent  the  work  of  the  infrequent  rains.    No  desert 
is  absolutely  rainless,  although  until  recently  it  was  the  fashion 
to  say  so.     Naturally  the  wind,  which  works  incessantly,  partly 
offsets  the  work  of  the  water.    Yet  the  wind  can  make  but  little 
impression  upon  the  general  outlines  of  the  dry  valleys.    They  re- 
main under  the  dominance  of  the  irregular  rains.     These  come 
sometimes  at  intervals  of  three  or  four  years,  again  at  intervals 
of  ten  to  fifteen  years,  and  some  parts  of  the  desert  have  probably 
been  rainless  for  a  hundred  years.     Some  specific  cases  are  dis- 
cussed in  the  chapter  on  Climate. 

The  large  valleys  of  the  desert  zone  have  been  cut  by  snow- 
fed  streams  and  then  partly  filled  again  so  that  deep  waste  lies  on 
their  floors  and  abuts  with  remarkable  sharpness  against  the  bor- 
dering cliffs  (Fig,  155).  Extensive  flats  are  thus  available  for 
easy  cultivation,  and  the  through-flowing  streams  furnish  abundant 
water  to  the  irrigating  canals.  The  alluvial  floor  begins  almost 
at  the  foot  of  the  st  jep  western  slope  of  the  lava  plateau,  but  it  is 
there  stony  and  coarse — htmce  Chuquibamba,  or  plain  of  stones 
(chuqui=stone ;  bamba=plain) .  Farther  down  and  about  half-way 
between  Chuquibamba  and  Aplao  (Camana  Quadrangle)  it  is  partly 
covered  with  fresh  mud  and  sand  flows  from  the  bordering  valley 
walls  and  the  stream  is  intrenched  two  hundred  feet,  A  few  miles 
above  Aplao  the  stream  emerges  from  its  narrow  gorge  and  thence- 
forth flows  on  the  surface  of  the  alluvium  right  to  the  sea.  Nar- 
row places  occur  between  Cantas  and  Aplao,  where  there  is  a  pro- 


116  THE  ANDES  OF  SOUTHERN  PERU 

jection  of  old  and  hard  quartzitic  rock,  and  again  above  Camana, 
where  the  stream  cuts  straight  across  the  granite  axis  of  the  Coast 
Range.  Elsewhere  the  rock  is  either  a  softer  sandstone  or  still 
unindurated  sands  and  gravels,  as  at  the  top  of  the  desert  series 
of  strata  that  are  exposed  on  the  valley  wall.  The  changing  width 
of  the  valley  is  thus  a  reflection  of  the  changing  hardness  of  the 
rock. 

There  is  a  wide  range  of  products  between  Chuquibamba  at 
10,000  feet  (3,050  m.)  at  the  head  of  the  valley  and  Camana  near 
the  valley  mouth.  At  the  higher  levels  fruit  will  not  grow — only 
alfalfa,  potatoes,  and  barley.  A  thousand  feet  below  Chuqui- 
bamba fruit  trees  appear.  Then  follows  a  barren  stretch  where 
there  are  mud  flows  and  where  the  river  is  intrenched.  Below 
this  there  is  a  wonderful  change  in  climate  and  products.  The 
elevation  falls  off  4,000  feet  and  the  first  cultivated  patches 
below  the  middle  unfavorable  section  are  covered  wdth  grape 
vines.  Here  at  3,000  feet  (900  m.)  elevation  above  the  sea  begin 
the  famous  vineyards  of  the  Majes  Valley,  which  support  a  wine 
industry  that  dates  back  to  the  sixteenth  century.  Some  of  the 
huge  buried  earthenware  jars  for  curing  the  wine  at  Hacienda 
Cantas  were  made  in  the  reign  of  Philip  II. 

The  people  of  Aplao  and  Camana  are  among  the  most  hospita- 
ble and  energetic  in  Peru,  as  if  these  qualities  were  but  the  re- 
flection of  the  bounty  of  nature.  Nowhere  could  I  see  evidences 
of  crowding  or  of  the  degeneracy  or  poverty  that  is  so  often  as- 
sociated wilh  desert  people.  Water  is  always  plentiful;  some- 
times indeed  too  plentiful,  for  floods  and  changes  in  the  bed  of 
the  river  are  responsible  for  the  loss  of  a  good  deal  of  land. 
This  abundance  of  water  means  that  both  the  small  and  the  large 
landowners  receive  enough.  There  are  none  of  the  troublesome 
official  regulations,  as  in  the  poorer  valleys  with  their  inevitable 
favoritism  or  downiiuhl  ui-nfl.  Vet  even  here  the  valley  is  not 
fully  occupied;  at  many  places  more  land  could  be  put  under 
cultivation.  The  Bolaunde  brothers  at  Cantas  have  illustrated 
this  in  their  new  cotton  plantation,  where  clearings  and  new  canals 
have  turned  into  cultivated  fields  tracts  long  covered  with  brush. 


THE  COASTAL  DESERT  117 

The  Majes  Valley  sorely  lacks  an  adequate  port.  Its  cotton, 
sugar,  and  wine  must  now  be  shipped  to  Camana  and  thence  to 
Mollendo,  either  by  a  small  bi-weekly  boat,  or  by  pack-train  over 
the  coast  trail  to  Quilca,  where  ocean  steamers  call.  This  is  so 
roundabout  a  way  that  the  planters  of  the  mid-valley  section  and 
the  farmers  of  the  valley  head  now  export  their  products  over  the 
desert  trail  from  Cantas  to  Vitor  on  the  Mollendo-Arequipa  rail- 
road, whence  they  can  be  sent  either  to  the  cotton  mills  or  the 
stores  of  Arequipa,  the  chief  distributing  market  of  southern 
Peru,  or  to  the  ocean  port. 

The  fpreshore  at  Camana  is  low  and  marshy  where  the  salt 
water  covers  the  outer  edge  of  the  delta.  In  the  hollow  between 
two  headlands  a  broad  alluvial  plain  has  been  formed,  through 
which  the  shallow  river  now  discharges.  Hence  the  natural  inden- 
tation has  been  filled  up  and  the  river  shoaled.  To  these  disad- 
vantages must  be  added  a  third,  the  shoaling  of  the  sea  bottom, 
which  compels  ships  to  anchor  far  off  shore.  Such  shoals  are  so 
rare  on  this  dry  and  almost  riverless  coast  as  to  be  a  menace  to 
navigation.  The  steamer  Tucapelle,  like  all  west-coast  boats,  was 
sailing  close  to  the  unlighted  shore  on  a  very  dark  night  in 
April,  1911,  when  the  usual  fog  came  on.  She  struck  the  reef  just 
otf  Camana.  Half  of  her  passengers  perished  in  trying  to  get 
through  the  tremendous  surf  that  broke  over  the  bar.  The  most 
practicable  scheme  for  the  development  of  the  port  would  seem  to 
be  a  floating  dock  and  tower  anchored  out  of  reach  of  the  surf, 
and  connected  by  cable  with  a  railway  on  shore.  Harbor  works 
would  be  extraordinarily  expensive.  The  valley  can  support  only 
a  modest  project. 

The  relations  of  Fig.  65,  representing  the  Camana-Vitor  re- 
gion, are  typical  of  southern  Peru,  with  one  exception.  In  a  few 
valleys  the  streams  are  so  small  that  but  little  water  is  ever  found 
beyond  the  foot  of  the  mountains,  as  at  Moquegua.  In  the  Chili 
Valley  is  Arequipa  (8,000  feet),  right  at  the  foot  of  the  big  cones 
of  the  Maritime  Cordillera  (see  Fig.  6).  The  green  valley  floor 
narrows  rapidly  and  cultivation  disappears  but  a  few  miles  below 
the  town.    Outside  the  big  valleys  cultivation  is  limited  to  the  best 


118 


THE  ANDES  OF  SOUTHERN  PERU 


spots  along  the  foot  of  the  Coast  Range,  where  thw  streams  or 
small  springs  derive  water  from  the  zone  of  clouds  and  fogs  on  the 
seaward  slopes  of  the  Coast  Range.  Here  and  there  are  olive 
groves,  a  vegetable  garden,  or  a  narrow  alfalfa  meadow,  watered 


^^iJnlTS   or  IRRIOABLF    LAND  J/ J    / 


1  ur.      !♦•  s 


'x     CIK>ltOINATeS    or  ICA 
lONC    TS'JO'  Wof C 


LIMITS    Of 
IRRKABLC  LAND 


IMICATED   LAND 


V\Q.  07 — Irrigated  and  irrigable  land  Fig,   68 — The  projected   canal   to  con- 

in  the  lea  Valley  of  the  coastal  desert  of       vey  water  from  the  Atlantic  slope  to  the 
Peru.  Pacific  slope  of  the  Maritime  Cordillera.* 

by  uncertain  springs  tliat  issue  below  the  hoHows  of  the  bordering 
mountains. 

In  central  and  iioi'lhcrn  I'cru  the  coastal  region  has  aspects 
quite  different  fioni  lliose  about  Camanj'i.  At  some*  places,  for 
exainjilc  north  of  Cci'i-o  A/ul,  the  main  s])ni"s  of  tlic  Cordillera 
extend  down  to  the  shore.  ^Phcrc  is  neither  a  h)\v  (^)ast  Range 
noi-  a  broad  (h'sei't  paiiipa.  In  such  i)hi('es  Hat  hand  is  I'onnd  only 
on  the  alhuial  I'ans  and  (h'ltas.  Lima  and  ('allao  arc  typical. 
Fig.  ()<»,  compih'd  from  Adams's  reports  on  the  water  resources  of 

'  FigH.  07  and  flR  are  from  Bol.  do  MinaH  d.-l  Pprrt,  1000.  No.  "M .  pp.  82  and  S4 
rpHpcctively. 


^1 


THE  COASTAL  DESEKP 


119 


the  coastal  region  of  Peru,  shows  this  distinctive  feature  of  the 
central  region.  Beyond  Salaverry  extends  the  northern  region, 
where  nearly  all  the  irrigated  land  is  found  some  distance  back 
from  the  shore.    The  farther  north  we  go  the  more  marked  is  this 


3M 
2M 
IM 

JAN 

FEB 

MARCH 

APRIL 

MAY 

JUNE 

JULY 

AUG 

SEPT 

OCT. 

NOV    !    DEC 

' 

r^ 

^m 

^. 

Fig.  69 — A  stream  of  the  intermittent  type  in  the  coastal  desert  of  Peru.     Depth 
of  water  in  the  Puira  River  at  Puira,  1905.    (Bol.  de  Minas  del  Peru,  1906,  No.  45,  p.  2.) 

feature,  because  the  coastal  belt  widens.  Catacaos  is  several  miles 
from  the  sea,  and  Piura  is  an  interior  place.  At  the  extreme  north, 
where  the  rains  begin,  as  at  Tumbez,  the  cultivated  land  once  more 
extends  to  the  coast. 

These  three  regions  contain  all  the  fertile  coastal  valleys  of 
Peru.     The   larger   ones   are   impressive — with   cities,   railways, 


JAN.         FEB        MARCH     APRIL        MAY       JUNE       JULY         AUG.        SEPT.        OCT 


Fig.  70 — A  stream  of  the  perennial  type  in  the  coastal  desert  of  Peru.  Depth  of 
water  in  the  Chira  River  at  Sullana,  1905.  Data  from  May  to  September  are  ap- 
proximate.     (Bol.  de  Minas  del  Perfl,  1906,  No.  45,  p.  2.) 

ports,  and  land  in  a  high  state  of  cultivation.  But  they  are  after^^ 
all  only  a  few  hundred  square  miles  in  extent.  They  contain  less  ; 
than  a  quarter  of  the  people.  The  whole  Pacific  slope  from  the 
crest  of  the  Cordillera  has  about  15,000  square  miles  (38,850  sq. 
km.),  and  of  this  only  three  per  cent  is  irrigated  valley  land,  as 
shown  in  Fig.  'o^.  Moreover,  only  a  small  additional  amount  may 
be  irrigated,  perhaps  one  half  of  one  per  cent.    Even  this  amount 


:-Li  V. 


120  THE  ANDES  OF  SOUTHERN  PERU 

may  be  added  not  only  by  a  better  use  of  the  water  but  also  by  the 
diversion  of  streams  and  lakes  from  the  Atlantic  to  the  Pacific. 
Figs.  67  and  68  represent  such  a  project,  in  which  it  is  proposed  to 
carry  the  water  of  Lake  Choclococha  through  a  canal  and  tunnel 
under  the  continental  divide  and  so  to  the  head  of  the  lea  Valley. 
A  little  irrigation  can  be  and  is  carried  on  by  the  use  of  well  water, 
but  this  will  never  be  an  important  source  because  of  the  great 
depth  to  the  ground  water,  and  the  fact  that  it,  too,  depends  ulti- 
mately upon  the  limited  rains. 

The  inequality  of  opportunity  in  the  various  valleys  of  the 
coastal  region  depends  in  large  part  also  upon  inequality  of 
river  discharge.  This  is  dependent  chiefly  upon  the  sources  of  the 
streams,  whether  in  sno^vy  peaks  of  the  main  Cordillera  with 
fairly  constant  run-off,  or  in  the  western  spurs  where  summer 
rains  bring  periodic  high  water.  A  third  type  has  high  water  dur- 
ing the  time  of  greatest  snow  melting,  combined  with  summer 
rains,  and  to  this  class  belongs  the  Majes  Valley  with  its  sources 
in  the  snow^-cap  of  Coropuna.  The  other  two  types  are  illustrated 
by  the  accompanying  diagrams  for  Puira  and  Chira,  the  former 
intermittent  in  flow,  the  latter  fairly  constant." 


»  The  Bolettn  de  Minas  del   PerG,  No.  34.   1905.  contains  a  graphic  representation 
of  the  rC'gime  of  the  Rio  Chili   at  Arequipa  for  the  years   1901-1905. 


OF  1911 


.-.  ^rae:- 


« 


CHAPTER  IX 
CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 

CLIMATIC    BELTS 

The  noble  proportions  of  the  Peruvian  Andes  and  their  posi- 
tion in  tropical  latitudes  have  given  them  climatic  conditions  of 
great  diversity.  Moreover,  their  great  breadth  and  continuously 
lofty  summits  have  distributed  the  various  climatic  types  over 
spaces  sufficiently  ample  to  affect  large  and  important  groups  of 
people.  When  we  add  to  this  the  fact  that  the  topographic  types 
developed  on  a  large  scale  are  distributed  at  varying  elevations, 
and  that  upon  them  depend  to  a  large  degree  the  chief  character- 
istics of  the  soil,  another  great  factor  in  human  distribution,  we 
are  prepared  to  see  that  the  Peruvian  Andes  afford  some  strik- 
ing illustrations  of  combined  climatic  and  topographic  control 
over  man. 

The  topographic  features  in  their  relations  to  the  people  have 
been  discussed  in  preceding  chapters.  "We  shall  now  examine  the 
corresponding  effects  of  climate.  It  goes  without  saying  that  the 
topographic  and  climaticr  controls  cannot  and  need  not  be  kept 
rigidly  apart.  Yet  it  seems  desirable,  for  all  their  natural  inter- 
dependence, to  give  them  separate  treatment,  since  the  physical 
laws  upon  which  their  explanations  depend  are  of  course  entirely 
distinct.  Further,  there  is  an  independent  group  of  human  re- 
sponses to  detailed  climati'!  f^ures  that  have  little  or  no  connec- 
tion with  either  topography  or  soil. 

The  chief  climatic  belts  ol  Peru  run  roughly  from  north  to 
south  in  the  direction  of  the  main  features  of  the  topography.  Be- 
tween 13°  and  18°  S.,  however,  the  Andes  run  from  northwest  to 
southeast,  and  in  short  stretches  nearly  west-east,  with  the  result 
that  the  climatic  belts  likemse  trend  westward,  a  condition 
well  illustrated  on  the  seventy-third  meridian.     Here  are  devel- 

121 


122  THE  ANDES  OF  SOUTHERN  PERU 

oped  important  climatic  features  not  found  elsewhere  in  Peru. 
The  trade  winds  are  greatly  modified  in  direction  and  effects ;  the 
northward-trending  valleys,  so  deep  as  to  be  secluded  from  the 
trades,  have  floors  that  are  nearly  if  not  quite  arid;  a  restricted 
coastal  region  enjoys  a  heavier  rainfall ;  and  the  snowline  is  much 
more  strongly  canted  from  west  to  east  than  anywhere  else  in  the 
long  belt  of  mountains  from  Patagonia  to  Venezuela.  These  ex- 
ceptional features  depend,  however,  upon  precisely  the  same  phys- 
ical laws  as  the  normal  climatic  features  of  the  Peruvian  Andes. 
They  can,  therefore,  be  more  easily  understood  after  attention  has 
been  given  to  the  larger  aspects  of  the  climatic  problem  of  which 
they  form  a  part. 

The  critical  relations  of  trade  winds,  lofty  mountains,  and 
ocean  currents  that  give  distinction  to  Peruvian  climate  are  shown 
in  Figs.  71  to  73.  From  them  and  Fig.  74  it  is  clear  that  the  two 
sides  of  the  Peruvian  mountains  are  in  sharp  contrast  climatically. 
,  The  eastern  slopes  have  almost  daily  rains,  even  in  the  dry  season, 
I  and  are  clothed  with  forest.  The  western  leeward  slopes  are  so 
dry  that  at  8,000  feet  even  the  most  drought-resisting  grasses 
stop — only  low  shrubs  live  below  this  level,  and  over  large  areas 
there  is  no  vegetation  whatever.  An  exception  is  the  Coast 
Range,  not  shown  on  these  small  maps,  but  exhibited  in  the  suc- 
ceeding diagram.  These  have  moderate  rains  on  their  seaward 
(westerly)  slopes  during  some  years  and  grass  and  shrubby 
vegetation  gi'ow  Ix'twccn  llic  arid  coastal  terraces  below  them 
and  llic  parclicd  desert  al)ove.  Tiie  greatest  variety  of  cliiiiatc  is 
enjoyed  by  the  iii(>unt:iiii  zone.  Its  deeixT  \'alh\vs  and  basins  de- 
scend to  tropica!  levels;  its  higher  ranges  and  peaks  are  snow-cov- 
ered. I>etween  are  the  eliniales  of  half  the  world  compressed,  it 
may  be,  Ix-tween  (i,()()()  and  ir),()0()  feet  of  elevation  and  with  ex- 
tremes only  a  day's  jonrney  apai't. 

In  tlie  explanation  of  these  contrasts  we  have  to  deal  witli  rela- 
tively simple  facts  :in(l  princljiles;  but  the  render  who  is  interested 
chiefly  in  the  lininan  asjX'cts  of  the  icLrion  should  turn  to  p.  138 
where  the  effects  of  tlie  clininte  on  jn;in  ai'e  set  forth.  The 
ascending   trades   on   the   eastern   slopes   pass   successively   into 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


123 


Fig.  71. 


Fig.   72. 


Fig.  73. 


Fig.  74. 


Fig.    71 — The    three   chief   topographic   regions   of   Peru. 

Fig.  72 — The  wind  belts  of  Peru  and  ocean  currents  of  adjacent  waters. 

Fig.    73 — The   climatic   belts   of    Peru. 

Fig.  74 — ^Belts  of  vegetation  in  Peru. 


124<  THE  ANDES  OF  SOUTHERN  PERU 

atmospheric  levels  of  diminisiiing  pressure;  hence  they  expand, 
deriving  the  required  energy  for  expansion  from  the  heat  of 
the  air  itself.  The  air  thereby  cooled  has  a  lower  capacity  for 
the  retention  of  water  vapor,  a  function  of  its  temperature; 
the  colder  the  air  the  less  water  vapor  it  can  take  up.  As"^ 
long  as  the  actual  amount  of  water  vapor  in  the  air  is  less 
(than  that  which  the  air  can  hold,  no  rain  falls.  But  the  cool- 
ing process  tends  constantly  to  bring  the  warm,  moist,  ascend- 
ing air  currents  to  the  limit  of  their  capacity  for  water  vapor 
by  diminishing  the  temperature.  Eventually  the  air  is  saturated 
and  if  the  capacity  diminishes  still  further  through  diminishing 
temperature  some  of  the  water  vapor  must  be  condensed  from  a 
gaseous  to  a  liquid  form  and  be  dropped  as  rain. 

The  air  currents  that  rise  thousands  of  feet  per  day  on  the 
eastern  slopes  of  the  Andes  pass  again  and  again  through  this 
practically  continuous  process  and  the  eastern  aspect  of  the  moun- 
tains is  kept  rain-soaked  the  whole  year  round.  For  the  trades 
here  have  only  the  rarest  reversals.  Generallj^  they  blow  from  the 
east  day  after  day  and  repeat  a  fixed  or  average  type  of  weather 
peculiar  to  that  part  of  the  tropics  under  their  steady  domination. 
During  the  southern  summer,  when  the  day-time  temperature  con- 
trasts between  mountains  and  plains  are  strongest,  the  force  of 
the  trade  wind  is  greatly  increased  and  likewise  the  rapidity  of  the 
rain-making  processes.  Hence  there  is  a  distinct  seasonal  differ- 
ence in  the  rainfall — what  we  call,  for  want  of  a  better  name,  a 
"wet"  and  a  "dry"  season. 

On  the  western  or  seaward  slopes  of  the  Peruvian  Andes  the 
trade  winds  descend,  and  the  process  of  rain-making  is  reversed 
to  one  of  rain-taking.  The  descending  air  currents  are  com- 
pressed as  they  reach  lower  levels  where  there  are  progressively 
higher  atmospheric  pressures.  The  energy  expended  in  the  proc- 
ess is  expressed  in  ilio  air  as  licnt,  wliciicc  llic  (IcsccTKliiii;'  air  gains 
steadily  in  Iciiipfi-aliii-c  and  capacity  for  walci-  vapor,  and  ihere- 
fore  is  a  drying  wind,  'i'lins  tlio  leeward,  weslern  slopes  of  the 
mountains  roceivo  lifih"  rain  and  tho  lowlands  on  that  side  are 
desert. 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


125 


THE    CLIMATE    OF    THE    COAST 

A  series  of  narrow  but  pronounced  climatic  zones  coincide  with 
the  topographic  subdivisions  of  the  western  slope  of  the  country 
between  the  crest  of  the  Maritime  Cordillera  and  the  Pacific  Ocean. 
This  belted  arrangement  is  diagrammatically  shown  in  Fig.  75. 
From  the  zone  of  lofty  mountains  with  a  well-marked  summer 
rainy  season  descent  is  made  by  lower  slopes  with  successively 


ZONE  OF 
COASTAL  TER- 
RACES 

RAIN  ONCE 

IN  MANY 

YEARS 

iZONEOFFOG- 
iCOVERED  MOUN- 
TAINS 

IRAINAT  INTER- 
VALS Of  5-10 
YEARS     5,( 

00' 

ZONE  OF  DESERT  PLAINS 

RAIN  AT  INTERVALS  OF  MANY  YEARS 

ZONEOFSTEEP 

VALLEYS 
YEARLY  RAINS 

ZONE  OF  LOFTY  MOUNTAINS  AND 

PLATEAUS       /-^^-^S:?!^ 
FREQUENT  RAINS  IN-^'Ci^^^^"'^^^^ 

SUMMERJUUHWV^^-^''^ 

^^^it-ig::::^^ 

PROFILE  OF  MAJES  VALLEY 

-'-"                                                                                         1 

Fig.  75 — Topographic  and  climatic  provinces  in  the  coastal  region  of  Peru.  The 
broadest  division,  into  the  zones  of  regular  annual  rains  and  of  irregular  rains,  occurs 
approximately  at  8,000  feet  but  is  locally  variable.  To  the  traveler  it  is  always  clearly 
defined  by  the  change  in  architecture,  particularly  of  the  house  roofs.  Those  of  the 
coast  are  flat;   those  of  the  sierra  are  pitched  to  facilitate  run  off. 


less  and  less  precipitation  to  the  desert  strip,  where  rain  is  only 
known  at  irregular  intervals  of  many  years '  duration.  Beyond  lies 
the  seaward  slope  of  the  Coast  Eange,  more  or  less  constantly 
enveloped  in  fog  and  receiving  actual  rain  every  few  years,  and 
below  it  is  the  very  narrow  band  of  dry  coastal  terraces. 

The  basic  cause  of  the  general  aridity  of  the  region  has  already 
been  noted ;  the  peculiar  circumstances  giving  origin  to  the  variety 
in  detail  can  be  briefly  stated.  They  depend  upon  the  meteorologic 
and  hydrographic  features  of  the  adjacent  portion  of  the  South 
Pacific  Ocean  and  upon  the  local  topography. 

The  lofty  Andes  interrupt  the  broad  sweep  of  the  southeast 
trades  passing  over  the  continent  from  the  Atlantic ;  and  the  wdnd 
circulation  of  the  Peruvian  Coast  is  governed  to  a  great  degree 
by  the  high  pressure  area  of  the  South  Pacific.  The  prevailing 
winds  blow  from  the  south  and  the  southeast,  roughly  paralleling 
the  coast  or,  as  onshore  winds,  making  a  small  angle  with  it. 
When  the  Pacific  high  pressure  area  is  best  developed  (during  the 
southern  winter),  the  southerly  direction  of  the  winds  is  empha- 


126 


THE  ANDES  OF  SOUTHERN  PERU 


sized,  a  condition  clearly  shown  on  the  Pilot  Charts  of  the  South 
Pacific  Ocean,  issued  by  the  U.  S.  Hydrographic  Office. 

The  hydrographic  feature  of  greatest  importance  is  the  Hum- 
''boldt  Current.    To  its  cold  waters  is  largely  due  the  remarkably 
low  temperatures  of  the  coast.'    In  the  latitude  of  Lima  its  mean 

surface  temperature  is  about 
10°  below  normal.  Lima  itself 
has  a  mean  annual  tempera- 
ture 4.6°  F.  below  the  theo- 
retical value  for  that  latitude, 
(12°  S.).  An  accompanying 
curve  shows  the  low  tem- 
perature of  Callao  during  the 
winter  months.  From  mid- 
June  to  mid- September  the 
mean  was  01°  F.,  and  the 
annual  mean  is  only  65.6°  F. 

Fig.  70 — Temperatures  at  C'iulao,  Junc- 
Septemb.r,    1912,    from    observations    taken       (18°      C).      The      rcductioU      in 

by  Captain  A.  Taylor,  of  Callao.    Air  tem-     temperature  is  accompauied  by 

peratures    are   shown    by    heavy    lines;    sea 

temperatures   by      light   lines.     In   view   of       a  rcductioU  in  the  Vapor  CapaC- 

the  scant  record   for  comparative  land  and       ..       ^^  ^j^^  SUpor-inCUmbcnt  air, 

water     temperatures     along     the     Peruvian  •' 

coast  tliis  record,  short  as  it  is,  has  special       an    effect    of    wllicll    mucll    liaS 

'"*<^'"<^''*^-  been  made   in  explanation   of 

the  west-coast  desert.  That  it  is  a  contributing  though  not  ex- 
clusive factor  is  demonstrated  in  Kig.  77.  Curve  A  represents 
tlie  h\T)othetical  change  of  temperature  on  a  mountainous  coast 
witli  1<'iiii)()rary  afternoon  oiislioi'c  winds  from  a  warm  sea. 
Curve  Jj  represents  the  change  of  tempernlui-c  if  tlie  sea  be 
cold  factual  case  of  Peru).  Tlie  more  ra])i(l  I'isc  of  curve  B 
lo  llic  right  of  X-X",  Hie  liiii'  of  1  i-;iiisilioii,  niid  its  higher  eleva- 
tion nhovc  its  foiiiici-  s;itiii-;iti()n  IcNcl,  ns  cont  i-.-istcd  with  A, 
indicates  gr<';i1ci-  diNiicss  (lowci-  i-clntixc  humidity).  There  has 
b.'cii  pfccipll.'ilir.ii  ill  ease  A,  Imt   ;i1   :i   liiglicr  tciiipcj-.'it urc,  hfuce 


•  Hann  (TInndhook  of  Climntolojry,  trnnHlnfed  by  R.  T).'  C  Ward,  New  York,  1903) 
indicates  n  rontrii)iitory  cnuHf  in  tlio  upwellinf;  of  <■<>],]  wntcr  ;ilonf,'  tlie  coast  caused 
bv  the  Hteady  weflterly  drift,  of   the  cqiiatorinl   cnrniit. 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


127 


more  water  vapor  remains  in  the  air  after  precipitation  has 
ceased.  Curve  B  ultimately  rises  nearly  to  the  level  of  A,  for 
with  less  water  vapor  in  the  air  of  case  B  the  temperature  rises 
more  rapidly  (a  general  law).  Moreover,  the  higher  the  tem- 
perature the  greater  the  radiation.  To  summarize,  curve  A  rises 
more  slowly  than  curve  B,  (1)  because  of  the  greater  amount 
of  water  vapor  it  contains,  which  must  have  its  temperature 
raised  with  that  of  the  air,  and  thus  absorbs  energy  which  would 


BELT  OF  FALLING  TEMPERATURES 
CLOUD  BANKS,HIGH  DEW  POINT 
ANDMODERATEPRECIPITATION 


BELT  OF  RISING  TEMPERATURES, 
CLEAR  SKIES,LOW  DEW  POINT, 
AND  ARIDITY 


SEASHORE 


COAST  RANGES 


SATURATION  TEMPERATURE- 
SATURATION  TEMPERATURE - 
DESERT 


Fig.  77 — To  show  progressive  lowering  of  saturation  temperature  in  a  desert  under 
the  influence  of  the  mixing  process  whereby  dry  and  cool  air  from  aloft  sinks  to  lower 
levels  thus  displacing  the  warm  surface  air  of  the  desert.  The  evaporated  moisture  of 
the  surface  air  is  thus  distributed  through  a  great  volume  of  upper  air  and  rain  becomes 
increasingly  rarer.  Applied  to  deserts  in  general  it  shows  that  the  effect  of  any 
cosmic  agent  in  producing  climatic  change  from  moist  to  dry  or  dry  to  moist  will 
be  disproportionately  increased.  The  shaded  areas  C  and  C  represent  the  fog-covered 
slopes  of  the  Coast  Range  of  Peru  as  shown  in  Fig.  92.  X — X'  represents  the  crest  of 
the  Coast  Range. 

otherwise  go  to  increase  the  temperature  of  the  air,  and  (2)  be- 
cause its  loss  of  heat  by  radiation  is  more  rapid  on  account  of  its 
higher  temperature.  We  conclude  from  these  principles  and  de- 
ductions that  under  the  given  conditions  a  cold  current  intensi- 
fies, but  does  not  cause  the  aridity  of  the  west-coast  desert. 

Curves  a  and  h  represent  the  rise  of  temperature  in  two  con- 
trasted cases  of.  warm  and  cold  sea  with  the  coastal  mountains 
eliminated,  so  as  to  simplify  the  principle  applied  to  A  and  B. 
The  steeper  gradient  of  h  also  represents  the  fact  that  the  lower 
the  initial  temperature  the  dryer  will  the  air  become  in  passing 
over  the  warm  land.  For  these  tw^o  curves  the  transition  line 
X-X'  coincides  mth  the  crest  of  the  Coast  Eange.  It  will  also  be 
seen  that  curve  a  is  never  so  far  from  the  saturation  level  as 


128 


THE  ANDES  OF  SOUTHERN  PERU 


9  a.m 


DEC,  JAN.,  1897-1900 

N 
3  p.m. 


8  a.m. 


JUNE  11-SEPT.  11,  1912 

N 
Noon 


Fio.  78 — Wind  roses  for  Calloo.  Tlio  figures  for  the  cnrlier  pe- 
riod (1807-1900)  are  drawn  from  dnta  in  tlie  lioleffn  de  la  Sociediid 
Grogrfifica  dc  Limn,  Vols.  7  and  H,  1H08-1900:  for  tlie  latU-r  period 
data  froin  obaervations  of  Cajitain  A.  'Jaylor,  of  Callno.  The  diam- 
eter of  the  circle  represents  the  proportioniit-e  nmnhir  of  ohnervationH 
when  calm  was  registered. 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


129 


curve  b.    Hence,  unusual  atmospheric  disturbances  would  result 
in  heavier  and  more  frequent  showers. 

Turning  now  to  local  factors  we  find  on  the  west  coast  a  re- 
gional topography  that  favors  a  diurnal  periodicity  of  air  move- 
ment. The  strong  slopes  of  the  Cordillera  and  the  Coast  Range 
create  up-slope  or  eastward  air  gradients  by  day  and  opposite 

OCT.-MARCH,  1893-'95 
2  p.m. 


APRIL-SEPT.,  1893- '95 
2  p.m. 


8  p.m 


Fig.  79 — Wind  roses  for  Mollendo.  The  figures  are  draA\Ti  from  data  in  Peruvian 
Meteorology  (1892-1895),  Annals  of  the  Astronomical  Observatory  of  Harvard  College, 
Vol.  39,  Pt.  2,  Cambridge,  Mass.,  1906.  Observations  for  an  earlier  period,  Feb. 
18e9-March  1890,  (Id.  Vol.  39,  Pt.  1,  Cambridge,  Mass.  1899)  record  S.  E.  wind  at 
2  p.  ra.  97  per  cent  of  the  observation  time. 


gradients  by  night.  To  this  circumstance,  in  combination  with 
the  low  temperature  of  the  ocean  water  and  the  direction  of  the 
prevailing  winds,  is  due  the  remarkable  development  of  the  sea- 
breeze,  without  exception  the  most  important  meteorological  fea- 
ture of  the  Peruvian  Coast.  Several  graphic  representations  are 
appended  to  show  the  dominance  of  the  sea-breeze  (see  wind  roses 


130 


THE  ANDES  OF  SOUTHERN  PERU 


for  Callao,  Mollendo,  Arica,  and  Iquique),  but  interest  in  the 
phenomenon  is  far  from  being  confined  to  the  theoretical.  Every- 
where along-  the  coast  the  virazon,  as  the  sea-breeze  is  called  in 
contradistinction  to  the  terral  or  land-breeze,  enters  deeply  into 
the  affairs  of  human  life.  According  to  its  strength  it  aids 
or  hinders  shipping;  sailing  boats  may  enter  port   on  it  or  it 


7  a.m. 


OCT.-MARCH 

N 


Fio.  HO — Wind  roses  for  tlic  suiniiu'r  and  wintor  seasons  of  tho  years  1!)1 1-1913. 
The  diameter  of  the  circl.'  in  cacli  case  shows  the  pro])ortion  of  calm.  Figures  are 
drawn  from  data  in  tlu;  Anuario  Meteorologieo  de  Cliilo,  rublications  No.  3,  (1911), 
C    (1!)I2)    and    l.'J    (1»1.'{),  Santiago,    1912,    1914.    1914. 

iiiny  he  .so  x-'iolciil,  as,  loi"  cxaiiiplc.  il  coimiioiily  is  al  l^isco, 
that  cargo  (•;iiiiio1  Itc  loaded  or  uiiloiidi'd  diiriiig  llic  ;i  rici'iiooii. 
()ii  tli«-  nitralc  paiiipii  of  iioi-tlicni  ('liilc  (I'd  to  !>.")'  S. )  it  not 
iiirr<'*pi('ii1l\-  l>rc;iks  willi  a  i'o;ii-  tlint  liorahls  its  coiiiiiig  an 
hour  ill  ;i(l\aiicc.  hi  tlic  Majcs  \  alley  (1*-'"  S.)  it  l»l(»\\s  gustily 
for  a  liair  lioiii-  ;iimI  ;il)oii1  noon  (ol'lcn  by  clcxcii  o'clock)  it 
settles    down    to    an    uncoinrorlahlc    gale.      Kor    an    liour    or    two 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


131 


before  the  sea-breeze  begins  the  air  is  hot  and  stifling,  and 
dust  clouds  hover  about  the  traveler.  The  maximum  tempera- 
ture is  attained  at  this  time  and  not  around  2,00  p.  m.  as  is  nor- 
mally the  case.  Yet  so  boisterous  is  the  noon  wind  that  the  laborers 
time  their  siesta  by  it,  and  not  by  the  high  temperatures  of  earlier 

OCT.-MARCH 

N  N  ^  N 


7  a.m 


2  p.m. 


Fig.  81 — Wind  roses  for  Iquique  for  the  summer  and  winter  seasons  of  the  years 
1911-1913.  The  diameter  of  the  circle  in  each  case  shows  the  proportion  of  calm. 
For   source  of  data  see   Fig.   80. 

hours.    In  the  afternoon  it  settles  do^vn  to  a  steady,  comfortable^ 
and  dustless  wind,  and  by  nightfall  the  air  is  once  more  calm. 

Of  highest  importance  are  the  effects  of  the  sea-breeze  on  pre- 
cipitation. The  bold  heights  of  the  Coast  Eange  force  the  nearly 
or  quite  saturated  air  of  the  sea-wind  to  rise  abruptly  several 
thousand  feet,  and  the  adiabatic  cooling  creates  fog,  cloud,  and 
even  rain  on  the  seaward  slope  of  the  mountains.  The  actual  form 
and  amount  of  precipitation  both  here  and  in  the  interior  region 
vary  greatly,  according  to  local  conditions  and  to  season  and  also 
from  year  to  year.     The  coast  changes  height  and  contour  from 


132 


THE  ANDES  OF  SOUTHERN  PERU 


place  to  place.  At  Arica  the  low  coastal  chain  of  northern  Chile 
terminates  at  the  Morro  de  Arica.  Thence  northward  is  a  stretch 
of  open  coast,  with  almost  no  rainfall  and  little  fog.  But  in  the 
stretch  of  coast  between  Mollendo  and  the  Majes  Valley  a  coastal 
range  again  becomes  prominent.  Fog  enshrouds  the  hills  almost 
daily  and  practically  every  year  there  is  rain  somewhere  along 
their  western  aspect. 

During  the  southern  winter  the  cloud  bank  of  the  coast  is  best 
developed  and  precipitation  is  greatest.    At  Lima,  for  instance, 


EASTEBiy  WINDS  FEeBU 


RAINY  SEASON  DRY  SEASON      ,-"— ^ 

scA  BRceze , *^  .,^-  •' 

HUMBOUII CUBBCnT .l^Tg^OAST  RANGC  -  DESERT  M«BITIMt  COBDILUB« 


Fig.  82 — The  wet  and  dry  seasons  of 
the  Coast  Range  and  the  Cordillera  are 
complementary  in  time.  The  "  wet " 
season  of  the  former  occurs  during  the 
southern  winter;  the  cloud  bank  on  the 
seaward  slopes  of  the  hills  is  best  devel- 
oped at  that  time  and  actual  rains  may 
occur. 


iaSTEBLY  WINDS ATHIGHELEVATIOM 


DRY  SEASON 

SEA  BREEZE 


RAINY  SEASON 


--Ne^.*-^ 


wiwmS^^^'- ^OAST  RANGT'deSeRT^^ ''■■f"^... MAnillMi CCJOIlLtB/ 


Fig.  83 — During  the  southern  summer 
the  seaward  slopes  of  the  Coast  Range  are 
comparatively  clear  of  fog.  Afternoon 
cloudiness  is  characteristic  of  the  desert 
and  increases  eastward  (compare  Fig. 
86),  the  influence  of  the  strong  sea  winds 
as  well  as  that  of  the  trades  (compare 
Fig.  93B)  being  felt  on  the  lower  slopes 
of  the  Maritime  Cordillera. 


the  clear  skies  of  March  and  April  begin  to  be  clouded  in  May,  and 
the  cloudiness  grows  until,  from  late  June  to  September,  the  sun 
is  invisible  for  weeks  at  a  time.  This  is  the  period  of  the  garua 
(mist)  or  the  ^'tiempo  de  lomas,"  the  ''season  of  the  hills,"  when 
the  moisture  clothes  them  with  verdure  and  calls  thither  the  herds 
of  the  coast  valleys. 

During  the  southern  summer  on  account  of  the  greater  relative 
differencH)  between  the  temperatures  of  land  and  water,  the  sea- 
breeze  attains  its  maximum  strength.  It  then  accomplishes  its 
greatest  work  in  the  desert.  On  the  pampa  of  La  Joya,  for  exam- 
ple, the  sand  dunes  move  most  rapidly  in  the  summer.  According 
to  the  Peruvian  Meteorological  Records  of  the  Harvard  Astronom- 
ical ()bservatory  the  average  movement  of  the  dunes  from  April 
to  September,  1900,  was  1.4  inches  per  day,  while  during  the  sum- 
mer months  of  the  same  year  it  was  2.7  inches.  In  close  agree- 
ment are  the  figures  for  the  wind  force,  the  record  for  whicli  also 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


133 


June,  July 


Tlie  relative  humidity 

Dec,  Jan. 
9  a.m. 


3  p.m. 


shows  that  95  per  cent  of  the  winds  with  strength  over  10  miles  per 
hour  blew  from  a  southerly  direction.  Yet  during  this  season  the 
coast  is  generally  clearest  of  fog  and  cloud.  The  explanation  ap- 
pears to  lie  in  the  exceedingly  delicate  nature  of  the  adjustments 
between  the  various  rain-making  forces 
of  the  air  from  the  sea  is  al- 
ways high,  but  on  the  im- 
mediate coast  is  slightly  less 
so  in  summer  than  in  win- 
ter. Thus  in  Mollendo  the 
relative  humidity  during  the 
winter  of  1895  was  81  per 
cent;  during  the  summer  78 
per  cent.  Moreover,  the 
temperature  of  the  Coast 
Range  is  considerably  higher 
in  summer  than  in  winter, 
and  there  is  a  tendency  to 
reevaporation  of  any  mois- 
ture that  may  be  blown 
against  it.  The  immediate 
shore,  indeed,  may  still  be 
cloudy  as  is  the  case  at  Cal- 
lao,  which  actually  has  its 
cloudiest  season  in  the  sum- 
mer, but  the  hills  are  com- 
paratively clear.  In  conse- 
quence the  sea-air  passes 
over  into  the  desert,  where 
the  relative  increase  in  tem- 
perature has  not  been  so 
great  (compare  Mollendo  and  La  Joya  in  the  curve  for  mean 
monthly  temperature),  with  much  higher  vapor  content  than  in 
winter.  The  relative  humidity  for  the  winter  season  at  La  Joya, 
1895,  was  42,5  per  cent;  for  the  suromer  season  57  per  cent.  The 
influence  of  the  great  barrier  of  the  Maritime  Cordillera,  aided 


9p.ni. 


jjCompletely 
3   Overcast 


Scale  of  Cloudiness 

[ZZI  Clear      [ElEl  0-2.5        1232.5-7.5    ^9.5-10 

Fig.  84 — Cloudiness  at  Callao.  Figures 
are  drawn  from  data  in  the  Boletfn  de  la 
Sociedad  Geografica  de  Lima,  Vols.  7  and  8, 
1898-1900.  They  represent  the  conditions  at 
tliroe  observation  hours  during  the  summers 
(Dec.,  Jan.)  of  1897-1898,  1898-1899,  1899- 
1900  and  the  winters  (June,  July)  of  1898  and 
1899. 


13i 


THE  ANDES  OF  SOUTHERN  PERU 


doubtless  by  convectional  rising,  causes  ascent  of  the  compara- 
tively humid  air  and  the  formation  of  cloud.  Farther  eastward, 
as  the  topographic  influence  is  more  strongly  felt,  the  cloudiness 

1894  1895 


Fig.  85 — Temperature  curves  for  ]\Iollcndo  (solid  lines)  and  La  Joya  (bidkon 
lines)  April,  1894,  to  December,  1895,  drawn  from  data  in  Peruvian  Meteorology,  1892- 
1895,  Annals  of  the  Astronomical  Observatory  of  Harvard  College,  Vol.  49,  Pt.  2, 
Cambridge,  Mass.,  1908.  The  approximation  of  the  two  curves  of  maximum  tempera- 
ture during  the  winter  montlis  contrasts  with  tlie  well-maintained  difference  in  minimum 
temperatures  throughout  the  year. 

increases  until  on  the  border  zone,  about  8,000  feet  in  elevation,  it 
may  thicken  to  actual  rain.  Data  have  been  selected  to  demon- 
strate this  eastern  gradation  of  meteorological  phenomena. 

1892  1893  1894  1895  „   ,    . 

8«»'«  o'  Ia  m!  .1 
Cloudmoa  ^' 


A  M 

Tl 

7] 

AIS 

ol 

[^ 

U  J 

[^ 

■ji] 

A 

m] 

[T 

J 

AIS 

0 

N 

D 

J 

F 

M 

'a 

M 

J 

J   A 

s 

0 

N 

D  J 

••■ 

'm 

A 

M 

J   J    A 

s 

o 

N 

I) 

_^ 

1 

X 

WINTER 

SI) 

MMER 

w 

INT 

ER 

SUM 

MER 

w 

NTER 

SUMMER 

W 

INTER 

A 

-/ 

^ 

V 

-N 

/■ 

J 

I 

,/ 

\ 

t 

-- 

^ 

-\ 

y 

V 

/ 

^ 

,Mol 

or 

d< 

/ 

/ 

\ 

' 

s 

/ 

V 

i 

\ 

t 

_. 

J 

N 

/ 

N 

1 

\ 

(\ 

J 

\ 

r\ 

r 

s< 

/- 

\ 

^ 

sj 

L 

I .. 

<'>'i4 

V 

-J 

^ 

r 

•f 

L. 

y 

V 

V 

>N 

.^ 

"' 

•- 

■ 

_3 

C 

- 

J 

_J 

■^ 

•^ 

~- 

•• 

J 

^ 

^ 

^ 

•"- 

-- 

_ 

I'kj.  H(; — Mean  monthly  cloudiness  for  Mollendo  (solid  line)  and  T.n  Joya  (broken 
line)  from  April,  1892,  to  DeeemlMT,  1H95.  Molk>ndo,  80  feet  elevation,  has  the  maximum 
winti'r  cIoudineHs  characteristic  of  the  seaward  slope  of  the  Coast  Range  (compare 
Fig.  82)  wliile  the  desert  station  of  La  Joya,  4,140  feet  elevation,  has  typical  summer 
cloudincHH  (compare  Fig.  8.3).  Figun-s  arc  drawn  from  data  in  Peruvian  Meteorology', 
1892-1895,  .Annals  of  the  Astronomical  f)bscrv:itory  of  llmv.inl  Colb-gc,  Vol.  49,  Pt.  2, 
Cambridge,  Mass.,  1908. 

At  IjH  .Joya,  a  station  on  the  desert  northeast  of  Mollendo  at 
an  elevation  of  4,140  feet,  cloudiness  is  always  slight,  but  it  in- 
creases markedly  (lurln.LC  llic  sihiijiut.     Caraveli,  at  an  altitude  of 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES 


135 


5,635  feet,''  and  near  the  eastern  border  of  the  pampa,  exhibits  a 
tendency  toward  the  climatic  characteristics  of  the  adjacent  zone. 
Data  for  a  camp  station  out  on  the  pampa  a  few  leagues  from 
the  town,  were  collected  by  Mr.  J.  P.  Little  of  the  staff  of  the 


8  a.m 


2  p.m. 


8  p.m. 


Fig.  87 — Wind  roses  for  La  Joya  for  the  period  April,  1892,  to  December,  1895. 
Compare  the  strong  afternoon  indraught  from  the  south  with  the  same  phenomenon 
at  Mollendo,  Fig.  79.  Figures  drawn  from  data  in  Peruvian  Meteorology,  1892-1895, 
Annals  of  the  Astronomical  Observatory  of  Harvard  College,  Vol.  39,  Pt.  2,  Cambridge, 
Mass.,  1906. 

Peruvian  Expedition  of  1912-13.  They  relate  to  the  period 
January  to  March,  1913.  Wind  roses  for  these  months  show  the 
characteristic  light  northwesterly  winds  of  the  early  morning 
hours,  in  sharp  contrast  with  the  strong  south  and  southwesterly 
indraught  of  the  afternoon.  The  daily  march  of  cloudiness  is 
closely  coordinated.  Quotations  from  Mr.  Little's  field  notes  fol- 
low: 

"In  the  morning  there  is  seldom  any  noticeable  w^nd.  A 
breeze  starts  at  10  a.  m.,  generally  about  180°  (i.  e.  due  south), 
increases  to  2  or  3  velocity  at  noon,  having  veered  some  25°  to  the 
southwest.  It  reaches  a  maximum  velocity  of  3  to  4  at  about  4.00 
p.  M.,  now  coming  about  225°  (i.  e.  southwest).    By  6  p.  m.  the  wind 


'  This  is  the   elevation   obtained  by  the  Peruvian   Expedition.     Raimondi's  figure 
(1,832  m.)    is  higher. 


136 


THE  ANDES  OF  SOUTHERN  PERU 


has  died  down  considerably  and  the  evenings  are  entirely  free 
from  it.  The  wind  action  is  about  the  same-  every  day.  It  is  not 
a  cold  w^ind  and,  except  with  the  fog,  not  a  damp  one,  for  I  have 
not  worn  a  coat  in  it  for  three  weeks.  It  has  a  free  unobstructed 
sweep  across  fairly  level  pampas.  ...  At  an  interval  of  every 
three  or  four  days  a  dense  fog  sweeps  up  from  the  southwest, 
dense  enough  for  one  to  be  easilj^  lost  in  it.    It  seldom  makes  even 


Fig.  88 — Wind  roses  for  a  station  on  the  eastern  border  of  the  Coast  Desert  near 
Caraveli  during  the  summer  (January  to  March)  of  1913.  Compare  witli  Fig.  87. 
Tlie  diameter  of  the  circle  in  each  case  represents  the  proportion  of  calm.  Note  tlie 
characteristic  morning  calm. 

a  sprinkle  of  rain,  but  carries  heavy  moisture  and  will  wet  a  man 
on  horseback  in  10  minutes.  It  starts  about  3  p.  m.  and  clears 
away  by  8.00  p.  m.  .  .  .  During  January,  rain  fell  in  camp  twice 
on  successive  days,  starting  at  3.00  p.  m.  and  ceasing  at  8.00  p.  m. 
It  was  merely  a  light,  steady  I'aiii,  more  tlie  outcome  of  a  dense 
fog  than  a  rain-cloud  of  quick  approach.  In  Caraveli,  itself,  I  am 
told  iliat  it  rnius  off  and  on  all  during  the  month  in  short,  light 
showers."  'I'll is  record  is  dated  early  in  February  and,  in  later 
notes,  tliat  month  and  March  are  recorded  rainless. 

Chosica  (elevation  (5,000  feet),  one  of  the  meteorological  sta- 
tions of  the  Harvard  A.stronomical  Oljsci-vatory,  is  still  nearer  the 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  137 

border.  It  also  lies  farther  north,  approximately  in  the  latitude 
of  Lima,  and  this  in  part  may  help  to  explain  the  greater  cloudi- 
ness and  rainfall.  The  rainfall  for  the  year  1889-1890  was  6.14 
inches,  of  which  3.94  fell  in  February.  During  *he  winter  months 
when  the  principal  wind  observations  were  taken,  over  90  per  cent 
showed  noon  winds  from  a  southerly  direction  while  in  the  early 


6.30-7  a.m. 


6  p.m. 


Cloudiness 


Completely- 
Overcast 


[ZIl  Clear  1113  0-2.5  E^  2.5-7.5  lilMl  7.5-10 

Fig.    89 — Cloudiness   at   the    desert   station    of    Fig.    88    (near   Caraveli),    for   the 
summer   (January  to  March)   of  1913. 


morning  northerly  winds  were  frequent.  It  is  also  noteworthy 
that  the  '^  directions  of  the  upper  currents  of  the  atmosphere  as 
recorded  by  the  motion  of  the  clouds  was  generally  between  N.  and 
E. ' '  Plainly  we  are  in  the  border  region  where  climatic  influences 
are  carried  over  from  the  plateau  and  combine  their  effects  Avith 
those  from  Pacific  sources.  Arequipa,  farther  south,  and  at  an 
altitude  of  7,550  feet,  resembles  Chosica.  For  the  years  1892  to 
1895  its  mean  rainfall  was  ^A  inches. 

Besides  the  seasonal  variations  of  precipitation  there  are 
longer  periodic  variations  that  are  of  critical  importance  on  the 
Coast  Range.  At  times  of  rather  regular  recurrence,  rains  that 
are  heavy  and  general  fall  there.  Every  six  or  eight  years  is  said 
to  be  a  period  of  rain,  but  the  rains  are  also  said  to  occur  some- 
times at  intervals  of  four  years  or  ten  years.  The  regularity  is 
only  approximate.  The  years  of  hea^dest  rain  are  commonly  as- 
sociated with  an  unusual  frequency  of  wdnds  from  the  north,  and 
an  abnormal  development  of  the  warm  current.  El  Nino,  from  the 


138 


THE  ANDES  OF  SOUTHERN  PERU 


Scale  of 
Cloudioess 


18S9  1890 

J     A     S     O    N    D     J     F   M    A    M     J      J 


Gulf  of  Gruayaquil.    Such  was  the  case  in  the  phenomenally  rainy 

year  of  1891.    The  connection  is  obscure,  but  undoubtedly  exists. 

The  effects  of  the  heavy  rains  are  amazing  and  appear  the 

more  so  because  of  the  extreme  aridity  of  the  country  east  of 

them.  During  the  mnter 
^  the  desert  traveler  finds  the 
air  temperature  rising  to 
uncomfortable  levels.  VegOr 
tation  of  any  sort  may  be 
completely  lacking.  As  he 
approaches  the  leeward 
slope  of  the  Coast  Range,  a 
cloud  mantle  full  of  refresh- 
ing promise  may  be  seen 
just  peeping  over  the  crest 
(Fig.  91).  Long,  slender 
cloud  filaments  project  east- 


WINTER 

— 1 — 1 — 

SUMMER 

WI 

NT 

iR 

,'* 

^ 

''\ 

/ 

/ 

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J 

'    / 

\ 

\ 

\ 

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\      \ 

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r- 

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FiQ.  90 — Cloudiness  at  Chosica,  July,  1889, 
to  September,  1890.  Chosica,  a  station  on 
the  Oroya  railroad  east  of  Lima,  is  situated 
on  the  border  region  between  the  desert  zone 
of  the  coast  and  the  mountain  zone  of  yearly 
rains.  The  minimum  cloudiness  recorded  about  ward  OVCr  tllO  margin  of  the 
11  a.  m.  is  shown  by  a  broken  line;   the  maxi-  ,        rm  i.  t     ~ 

mum  cloudiness,  about  7  p.  m.,  by  a  dotted     c^Gsert.     They  are  traveling 

line,  and  the  mean  for  the  24  hours  by  a  heavy  rapidly  but  they  UCVCr  ad- 
solid  line.  The  curves  are  drawn  from  data  „  j.i  i  i. 
in  Peruvian  Meteorologjs  1SS9-1890,  Annals  VaUCC  far  OVCr  the  hot 
of  the  Astronomical  Observatory  of  Harvard  wastcS,  for  tlicir  Castcm 
College,  Vol.  39,  Pt.  1,  Cambridge,  Mass.,  1899.  .                                ,        ,, 

^ '  '        '  °  margins  are  constantly  un- 

dergoing evaporation.  At  times  the  top  of  the  cloud  bank  rises 
well  above  the  crest  of  the  Coast  Range,  and  it  scoms  to  the  man 
from  the  temperate  zone  as  if  a  great  thunderstorm  were  rising  in 
the  west.  But  for  all  their  menace  of  wind  and  rain  the  clouds 
never  get  beyond  the  desert  outposts.  Tn  the  summer  season  the 
aspect  changes,  the  heavy  yellow  sky  of  the  desert  displaces  the 
murk  of  the  coastal  mountains  and  the  bordering  sea. 

It  is  an  age-old  strife  roiunvod  every  year  and  limited  to  a  nar- 
row field  of  ,'iefion,  woiidcrriilly  cnsy  to  observe.  We  saw  it  in  its 
most  striking  form  at  Iho  ond  of  1he  winter  season  in  October, 
1011,  and  for  more  llian  a  day  walched  Ihe  dark  clouds  rise  omi- 
nously only  to  melt  into  nothing  where  <ho  descrf  liolds  sway.  At 
night  we  camped  beside  a  scum-coated  pool  of  alkali  water  no 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  139 

larger  than  a  wash  basin.  It  lay  in  a  valley  that  headed  in  the 
Coast  Range,  and  carried  do^vn  into  the  desert  a  mere  trickle  that 
seeped  through  the  gravels  of  the  valley  floor.  A  little  below  the 
pool  the  valley  cuts  through  a  mass  of  granite  and  becomes  a  steep- 
walled  gorge.  The  bottom  is  clogged  with  waste,  here  boulders, 
there  masses  of  both  coarse  and  fine  alluvium.  The  water  in  the 
valley  was  quite  incapable  of  accomplishing  any  work  except  that 
associated  with  solution  and  seepage,  and  we  saw  it  in  the  wet 
season  of  an  unusually  wet  year.  Clearly  there  has  been  a  diminu- 
tion in  the  water  supply.  But  time  prevented  us  from  explor- 
ing this  particular  valley  to  its  head,  to  see  if  the  reduction 
were  due  to  a  change  of  climate,  or  only  to  capture  of  the 
head-waters  by  the  vigorous  rain-fed  streams  that  enjoy  a  favora- 
ble position  on  the  wet  seaward  slopes  and  that  are  extending 
their  watershed  aggressively  toward  the  east  at  the  expense  of 
their  feeble  competitors  in  the  dry  belt^ 

An  early  morning  start  enabled  me  to  witness  the  whole  series 
of  changes  between  the  clear  night  and  the  murky  day,  and  to  pass 
in  twelve  hours  from  the  dry  desert  belt  through  the  wet  belt,  and 
emerge  again  into  the  sunlit  terraces  at  the  western  foot  of  the 
Coast  Range.  Two  hours  before  daylight  a  fog  descended  from 
the  hills  and  the  going  seemed  to  be  curiously  heavy  for  the  beasts. 
At  daybreak  my  astonishment  was  great  to  find  that  it  was  due 
to  the  distinctly  moist  sand.  We  were  still  in  the  desert.  There 
was  not  a  sign  of  a  bush  or  a  blade  of  grass.  Still,  the  surface 
layer,  from  a  half  inch  to  an  inch  thick,  was  really  wet.  The  fog 
that  overhung  the  trail  lifted  just  before  sunrise,  and  at  the  first 
touch  of  the  sun  melted  a'way  as  swiftly  as  it  had  come.  With  it 
went  the  surface  moisture  and  an  hour  after  sunrise  the  dust  was 
once  more  rising  in  clouds  around  us. 

We  had  no  more  than  broken  camp  that  morning  when  a 
merchant  with  a  pack-train  passed  us,  and  shouted  above  the 
bells  of  the  leading  animals  that  we  ought  to  hurry  or  we  should 
get  caught  in  the  rain  at  the  pass.  My  guide,  w^ho,  like  many  of 
his  kind,  had  never  before  been  over  the  route  he  pretended  to 
know,  asked  him  in  heaven's  name  what  drink  in  distant  Camana 


140  THE  ANDES  OF  SOUTHERN  PERU 

whence  lie  had  come  produced  such  astonishing  effects  as  to  make 
a  man  talk  about  rain  in  a  parched  desert.  We  all  fell  to  laugh- 
ing and  at  our  banter  the  stranger  stopped  his  pack-train  and 
earnestly  urged  us  to  hurry,  for,  he  said,  the  rains  beyond  the  pass 
were  exceptionally  heavy  this  year.  We  rode  on  in  a  doubtful 
state  of  mind.  I  had  heard  about  the  rains,  but  I  could  not  be- 
lieve that  they  fell  in  real  showers ! 

About  noon  the  cloud  bank  darkened  and  overhung  the  border 
of  the  desert.  Still  the  sky  above  us  was  clear.  Then  happened 
what  I  can  yet  scarcely  believe.  We  rode  into  the  head  of  a  tiny 
valley  that  had  cut  right  across  the  coast  chain.  A  wisp  of  cloud, 
an  outlier  of  the  main  bank,  lay  directly  ahead  of  us.  There 
were  grass  and  bushes  not  a  half-mile  below  the  bare  dry  spot  on 
which  we  stood.  We  were  riding  down  toward  them  when  of  a 
sudden  the  wind  freshened  and  the  cloud  wisp  enveloped  us,  shut- 
ting out  the  view,  and  ten  minutes  later  the  moisture  had  gath- 
ered in  little  beads  on  the  manes  of  our  beasts  and  the  trail  be- 
came slippery.  In  a  half-hour  it  was  raining  and  in  an  hour  we 
were  in  the  midst  of  a  heavy  doAvnpour.  We  stopped  and  pas- 
tured our  famished  beasts  in  luxuriant  clover.  While  they  gorged 
themselves  a  herd  of  cattle  drifted  along,  and  a  startled  band  of 
burros  that  suddenly  confronted  our  beasts  scampered  out  of  sight 
in  the  heavy  mist.  Later  we  passed  a  herdsman's  hut  and  long 
before  wo  reached  him  lie  shouted  to  us  to  alter  our  course,  for 
just  ahead  the  old  trail  was  wet  and  treacherous  at  this  time 
of  year.  The  warning  came  too  late.  Several  of  our  beasts  lost 
their  footing  and  half  rolled,  half  slid,  down  hill.  One  turned  com- 
pletely over,  pack  and  all,  and  lay  in  the  soft  mud  calmly  taking 
advantage  of  the  delay  to  pluck  a  few  additional  nioullifuls  of 
grass.  We  were  glad  to  reach  firmer  ground  on  the  other  side  of 
til*'  valley. 

The  herdsmen  were  a  hospitable  lot.  Thoy  had  come  from 
Camana  and  rarely  saw  travelers.  Their  single  roomed  hut  was 
mired  so  deeply  1liat  one  found  it  hard  to  decide  whether  to  take 
shelter  from  the  rain  inside  or  escape  the  mud  by  st;mding  in  the 
rain  outside.    They  made  a  little  so-called  cheese,  rounded  up  and 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  141 

counted  the  cattle  on  clear  days,  drove  them  to  the  springs  from 
time  to  time,  and  talked  incessantly  of  the  wretched  rains  in  the 
hills  and  the  delights  of  dry  Camana  down  on  the  coast.  We  could 
not  believe  that  only  some  hours'  traveling  separated  two  locali- 
ties so  wholly  unlike. 

The  heavy  showers  and  luxuriant  pastures  of  the  wet  years 
and  the  light  local  rains  of  the  dry  years  endow  the  Coast  Eange 
with  many  peculiar  geographic  qualities.  The  heavy  rains  pro- 
vide the  desert  people  at  the  foot  of  the  mountains  such  a  wealth 
of  pasture  for  their  burdensome  stock  as  many  oases  dwellers 
possess  only  in  their  dreams.  From  near  and  far  cattle  are  driven 
to  the  wet  hill  meadow^s.  Some  are  even  brought  in  from  distant 
valleys  by  sea,  yet  only  a  very  small  part  of  the  rich  pastures  can 
be  used.  It  is  safe  to  say  that  they  could  comfortably  support  ten 
times  the  number  of  cattle,  mules,  and  burros  that  actually  graze 
upon  them.  The  grass  would  be  cut  for  export  if  the  weather 
were  not  so  continually  wet  and  if  there  were  not  so  great  a  mix- 
ture of  weeds,  flowers,  and  shrubs. 

Then  come  the  dry  years.  The  surplus  stock  is  sold,  and  w^hat 
remains  is  always  maintained  at  great  expense.  In  1907  I  saw 
stock  grazing  in  a  small  patch  of  dried  vegetation  back  of  Mol- 
lendo,  although  they  had  to  be  driven  several  miles  to  water.  They 
looked  as  if  they  were  surviving  with  the  greatest  difficulty  and 
their  restless  search  for  pasture  was  like  the  search  of  a  desper- 
ate hunter  of  game.  In  1911  the  same  tract  was  quite  devoid  of 
grass,  and  except  for  the  contour-like  trails  that  completely  cov- 
ered the  hills  no  one  would  even  guess  that  this  had  formerly  been 
a  cattle  range.  The  same  year,  but  five  months  later,  a  carpet 
of  grass,  bathed  in  heavy  mist,  covered  the  soil ;  a  trickle  of  water 
had  collected  in  pools  on  the  valley  floor ;  several  happy  families 
from  the  town  had  laid  out  a  prosperous-looking  garden;  there 
were  romping  children  w^ho  showed  me  where  to  pick  up  the  trail 
to  the  port ;  on  every  hand  w^as  life  and  activity  because  the  rains 
had  returned  bringing  plenty  in  their  train.  I  asked  a  native  how 
often  he  was  prosperous. 

''Segun   el   temporal   y   la   Providencia"    (according   to   the 


142  THE  ANDES  OF  SOUTHERN  PERU 

weather  and  to  Providence),  lie  replied,  as  he  pointed  significantly 
to  the  pretty  green  hills  crowned  with  gray  mist. 

It,  therefore,  seems  fortunate  that  the  Coast  Range  is  so  placed 
as  to  intercept  and  concentrate  a  part  of  the  moisture  that  the  sea- 
winds  carry,  and  doubly  fortunate  that  its  location  is  but  a  few 
miles  from  the  coast,  thereby  giving  temporary  relief  to  the  rela- 
tively crowded  people  of  the  lower  irrigated  valleys  and  the  towns. 
The  wet  years  formerly  developed  a  crop  of  prospectors.  Pack 
animals  are  cheaper  when  there  is  good  pasture  and  they  are  also 
easier  to  maintain.  So  w^hen  the  rains  came  the  hopeful  pick-and- 
shovel  amateurs  began  to  emigrate  from  the  to\^^ls  to  search  for 
ore  among  the  discolored  bands  of  rock  intruded  into  the  granite 
masses  of  the  coastal  hills.  However,  the  most  likely  spots  have 
been  so  thoroughly  and  so  unsuccessfully  prospected  for  many 
years  that  there  is  no  longer  any  interest  in  the  "mines." 

Transportation  rates  are  still  most  intimately  related  to  the 
^rains.  My  guide  had  two  prices — a  high  price  if  I  proposed  to 
enter  a  town  at  night  and  thus  require  him  to  buy  expensive 
forage ;  a  low  price  if  I  camped  in  the  hills  and  reached  the  town 
in  time  for  him  to  return  to  the  hills  with  his  animals.  Inquiry 
showed  that  this  was  the  regular  custom.  I  also  learned  that  in 
packing  goods  from  one  part  of  the  coast  to  another  forage  must 
be  carried  in  dry  years  or  the  beasts  required  to  do  without. 
In  wet  years  by  a  very  slight  detour  the  packer  has  his  beasts  in 
good  pasture  that  is  free  for  all.  The  merchant  who  dispatches 
the  goods  may  find  his  charges  nearly  doubled  in  extremely  dry 
years.  Ooods  are  more  expensive  and  there  is  a  decreased  con- 
sumption. 'I'lif  offccts  of  the  rains  are  thus  transmitted  from  one 
to  another,  until  at  last  nearly  all  the  luciiibrrs  of  a  couinninity 
arc  bearing  a  share  of  the  burdens  imposed  ])y  drought.  As  al- 
ways there  are  a  few  wlio  prosper  in  spite  of  the  ill  wind.  If  the 
pastures  fail,  live  stock  7nust  be  sold  and  the  dealers  ship  south 
to  the  nitrate  ports  or  north  to  the  large  coast  towns  of  Peru, 
where  there  is  always  a  demand.  Their  business  is  most  active 
wlion  it  is  dry  or  rather  at  the  beginning  of  the  dry  period.  Also 
if  transi)orl  by  l.ind  routes  becomes  too  expensive  the  small  trad- 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  143 

ers  turn  to  the  sea  routes  and  the  carriers  have  an  increased  busi- 
ness. But  so  far  as  I  have  been  able  to  learn,  dry  years  favor 
only  a  few  scattered  individuals. 

To  the  traveler  on  the  west  coast  it  is  a  source  of  constant  sur- 
prise that  the  sky  is  so  often  overcast  and  the  ports  hidden  by  fog, 
while  on  every  hand  there  are  clear  evidences  of  extreme  aridity. 
Likewise  it  is  often  inquired  why  the  sunsets  there  should  be  often 
so  superlatively  beautiful  during  the  winter  months  when  the 
coast  is  fog  bound.  Why  a  desert  when  the  air  is  so  humid?  "Why 
striking  sunsets  when  so  many  of  the  days  are  marked  by  dull 
skies?  As  we  have  seen  in  the  first  part  of  this  chapter,  the  big 
desert  tracts  lie  east  of  the  Coast  Bange,  and  there,  excepting 
slight  summer  cloudiness,  cloudless  skies  are  the  rule.  The  des- 
ert just  back  of  the  coast  is  in  many  parts  of  Peru  only  a  narrow 
fringe  of  dry  marine  terraces  quite  unlike  the  real  desert  in  type 
of  weather  and  in  resources.  The  fog  bank  overhanging  it 
forms  over  the  Humboldt  Current  which  lies  off  shore;  it  drifts 
landward  with  the  onshore  wind ;  it  forms  over  the  up  welling  cold 
water  between  the  current  and  the  shore;  it  gathers  on  the  sea- 
ward slopes  of  the  coastal  hills  as  the  inflowing  air  ascends  them 
in  its  journey  eastward.  Sometimes  it  lies  on  the  surface  of  the 
land  and  the  water;  more  frequently  it  is  some  distance  above 
them.  On  many  parts  of  the  coast  its  characteristic  position  is 
from  2,000  to  4,000  feet  above  sea  level,  descending  at  night  nearly 
or  quite  to  the  surface,  ascending  by  day  and  sometimes  all  but 
disappearing  except  as  rain-clouds  on  the  hills.^  Upon  the  local 
behavior  of  the  fog  bank  depends  in  large  measure  the  local  cli- 
mate.   A  general  description  of  the  coastal  climate  will  have  many 


•  According  to  Ward's  observations  the  base  of  the  cloud  belt  averages  between 
2,000  and  3,000  feet  above  sea  level  (Climatic  Notes  Made  During  a  Voyage  Around 
South  America,  Journ.  of  School  Geogr.,  Vol.  2,  1898).  On  the  south  Peruvian  coast, 
specifically  at  Mollendo,  Middendorf  found  the  cloud  belt  beginning  about  1,000  feet 
and  extending  upwards  to  elevations  of  3,000  to  4,000  feet.  At  Lima  the  clouds  descend 
to  lower  levels  (EI  Clima  de  Lima,  Bol.  See  Geogr.  de  Lima,  Vol.  15,  1904).  In 
the  third  edition  of  his  Siid-  und  Mittclaraerika  (Leipzig  and  Vienna,  1914)  Sievers 
says  that  at  Lima  in  the  winter  the  cloud  on  the  coast  does  not  exceed  an  elevation 
of  450  m.  (1,500  feet)  while  on  the  hills  it  lies  at  elevations  between  300  and  700  m. 
(1,000  and  2,300  feet). 


Ii4<  THE  ANDES  OF  SOUTHERN  PERU 

exceptions.  The  physical  principles  involved  are,  however,  the 
same  everywhere.  I  take  for  discussion  therefore  the  case  illus- 
trated by  Fig.  92,  since  this  also  displays  with  reasonable  fidelity 
the  conditions  along  that  part  of  the  Peruvian  coast  between 
Camana  and  Mollendo  which  lies  in  the  field  of  work  of  the  Yale 
Peruvian  Expedition  of  1911. 

Three  typical  positions  of  the  fog  bank  are  shown  in  the  figiire, 
and  a  fourth — that  in  which  the  bank  extends  indefinitely  west- 
ward— may  be  supplied  by  the  imagination. 

If  the  cloud  bank  be  limited  to  C  only  the  early  morning  hours 
at  the  port  are  cloudy.  If  it  extend  to  B  the  sun  is  obscured  until 
midday.  If  it  reach  as  far  west  as  A  only  a  few  late  afternoon 
hours  are  sunny.  Once  in  a  while  there  is  a  sudden  splash  of  rain 
^a  few  drops  which  astonish  the  traveler  who  looks  out  upon  a 
parched  landscape.  The  smaller  drops  are  evaporated  before 
reaching  the  earth.  In  spite  of  the  ever-present  threat  of  rain  the 
coast  is  extremely  arid.  Though  the  vegetation  appears  to  bo 
dried  and  burned  up,  the  air  is  humid  and  for  months  the  sky  may 
be  overcast  most  of  the  time.  So  nicely  are  the  rain-making  con- 
ditions balanced  that  if  one  of  our  ordinary  low-pressure  areas, 
or  so-called  cyclonic  storms,  from  the  temperate  zone  were  set  in 
motion  along  the  foot  of  the  mountains,  the  resulting  deluge  would 
immediately  lay  the  coast  in  ruins.  The  cane-thatched,  mud- 
walled  huts  and  houses  would  crumble  in  the  heavy  rain  like  a 
child's  sand  pile  before  a  rising  sea;  the  alluvial  valley  land  would 
be  coated  with  infertile  gravel;  and  mighty  rivers  of  sand,  now 
delicately  poised  on  arid  slopes,  would  inundate  large  tracts  of 
fertile  soil. 

If  the  fog  and  cloud  l)ank  extend  westward  indefinitely,  the  en- 
tire day  may  be  overcast  or  the  sun  appear  for  a  few  moments 
only  through  occasional  rifts.  Generally,  also,  it  will  make  an  ap- 
pearance just  before  sunset,  its  red  disk  completely  filling  the  nar- 
row space  between  the  under  surface  of  the  clouds  and  the  water. 
I  have  repeatedly  seen  the  ship's  passengers  and  even  the  crew 
leave  the  dinner  table  and  collect  in  wondering  groups  about  the 
port-holes  and  doorways  the  better  to  see  the  marvelous  play  of 


Fig.  91. 


ZDNEOFCOASTALTERRACES 

DRY  UNDERNEATH  FOG-BANK 
?>^'     FOG-BANK  BETWEEN  2;000  AND'4,0b(iFbET 

A"'"     ^   :  :.,,"''  'B  .  ■  'C- 


ZONE  OF  SUBDUED  COASTAL  MOUNTAINS 

WET  SEAWARD  ASPECT        DRY  LANDWARD  ASPECT 


DESERT  ZONE 


.TyPES  OF  STREAM  Profiles 


Fio.  92. 


Fig.  91 — Looking  clown  the  canyon  of  the  IVIajes  River  to  the  edge  of  the  cloud 
bank  formed  against  the  Coast  Range  back  of  Camana. 

Fig.  02 — Topographic  and  climatic  cross-section  to  show  the  varying  positions  of 
the  cloud  bank  on  the  coast  of  Peru,  the  dry  terrace  region,  and  the  types  of  stream 
profiles  in  the  various  belts. 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  145 

colors  between  sky  and  sea.  It  is  impossible  not  to  be  profoundly 
moved  by  so  majestic  a  scene.  A  long  resplendent  path  of  light 
upon  the  water  is  reflected  in  the  clouds.  Each  cloud  margin  is 
tinged  with  red  and,  as  the  sun  sinks,  the  long  parallel  bands  of 
light  are  shortened  westw^ard,  changing  in  color  as  they  go,  until 
at  last  the  full  glory  of  the  sunset  is  concentrated  in  a  blazing  arc 
of  reds,  yellows,  and  purples,  that  to  most  people  quite  atones  for 
the  dull  gray  day  and  its  humid  air. 

At  times  the  clouds  are  broken  up  by  the  winds  and  scattered 
helter-skelter  through  the  west.  A  few  of  them  may  stray  into 
the  path  of  the  sun  temporarily  to  hide  it  and  to  reflect  its  pri- 
mary colors  when  the  sun  reappears.  From  the  main  cloud  masses 
there  reach  out  slender  wind-blown  streamers,  each  one  delicately 
lighted  as  the  sun's  rays  filter  through  its  minute  water  particles. 
Many  streamers  are  visible  for  only  a  short  distance,  but  when 
the  sun  catches  them  their  filmy  invisible  fingers  become  delicate 
bands  of  light,  some  of  which  rapidly  grow  out  almost  to  the  dome 
of  the  sky.  Slowly  they  retreat  and  again  disappear  as  the  rays 
of  the  sun  are  gradually  shut  off  by  the  upturning  curve  of  the 
earth. 

The  unequal  distribution  of  precipitation  in  the  climatic  zones 
of  western  Peru  has  important  hydrographic  consequences.  These 
will  now  be  considered.  In  the  preceding  figure  four  types  of 
stream  profiles  are  displayed  and  each  has  its  particular  relation 
to  the  cloud  bank.  Stream  1  is  formed  wholly  upon  the  coastal 
terraces  beneath  the  cloud  bank.  It  came  into  existence  only 
after  the  uplift  of  the  earth 's  crust  that  brought  the  wave-cut  plat- 
forms above  sea  level.  It  is  extremely  youthful  and  on  account 
first  of  the  small  seepage  at  its  headquarters — it  is  elsewhere 
wholly  w^ithout  a  tributary  water  supply — and,  second,  of  the  re- 
sistant granite  that  occurs  along  this  part  of  the  coast,  it  has  very 
steep  and  irregular  walls  and  an  ungraded  floor.  Many  of  these 
"quebradas"  are  difficult  to  cross.  A  few  of  them  have  fences 
built  across  their  floors  to  prevent  the  escape  of  cattle  and  burros 
that  wander  down  from  the  grassy  hills  into  the  desert  zone. 
Others  are  partitioned  off  into  corrals  by  stone  fences,  the  steep 


146  THE  ANDES  OF  SOUTHERN  PERU 

walls  of  the  gorge  preventing  the  escape  of  the  cattle.  To  these 
are  driven  the  market  cattle,  or  mules  and  burros  that  are  re- 
quired for  relays  along  the  shore  trail. 

^  Stream  2  heads  in  the  belt  of  rains.  Furthermore  it  is  a  much 
older  stream  than  1,  since  it  dates  back  to  the  time  when  the  Coast 
Range  was  first  formed.  It  has  ample  tributary  slopes  and  a  large 
number  of  small  valleys.  A  trickle  of  water  flows  down  to  become 
lost  in  the  alluvium  of  the  lower  part  of  the  valley  or  to  reappear 
in  scattered  springs.  AYhere  springs  and  seepage  occur  together, 
an  olive  grove  or  a  garden  marks  the  spot,  a  corral  or  two  and  a 
mud  or  stone  or  reed  hut  is  near  by,  and  there  is  a  tiny  oasis. 
Some  of  these  dots  of  verdure  become  so  dry  during  a  prolonged 
drought  that  the  people,  long-established,  move  aw^ay.  To  others 
the  people  return  periodically.  Still  others  support  permanent 
settlements. 

,y  Stream  3  has  still  greater  age.  Its  only  competitors  are  the 
feeble,  almost  negligible,  streams  that  at  long  intervals  flow  east 
toward  the  dry  zone.  Hence  it  has  cut  back  until  it  now  heads  in 
the  desert.  Its  widely  branched  tributaries  gather  moisture  from 
large  tracts.  There  is  running  w^ater  in  the  valley  floor  even  down 
in  the  terrace  zone.  At  least  there  are  many  dependable  springs 
and  the  permanent  homes  that  they  always  encourage.  A  valley 
of  this  type  is  always  marked  by  a  well-defined  trail  that  leads 
from  settlement  to  settlement  and  eastward  over  the  "pass"  to 
the  desert  and  the  Andean  towns. 

'^Stream  4  is  a  so-called  "antecedent"  stream.  It  existed  be- 
fore the  Coast  Range  was  uplifted  and  cut  its  channel  downward 
as  the  mountains  rose  in  its  path.  The  stretch  where  it  crosses 
the  mountains  may  be  a  canyon  with  a  narrow,  rocky,  and  unculti- 
vable  floor,  so  that  the  valley  trails  rise  to  a  pass  like  that  at  the 
head  of  stream  3,  and  descend  again  lo  ilio  settlements  at  the 
moutli  of  4.  There  is  in  this  last  type  an  abundance  of  water,  for 
tlic  sources  of  the  stream  are  in  the  zone  of  permanent  snows  and 
frequent  winter  rains  of  the  lofty  Cordillera  of  the  Andes.  The 
settlements  along  this  stream  are  continuous,  except  where  shut- 
ins  occur — narrow,  rocky  defiles  caused  by  more  resistant  rock 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  147 

masses  in  the  path  of  the  stream.  Here  and  there  are  villages. 
The  streams  have  fish.  When  the  water  rises  the  river  may  be 
unfordable  and  people  on  opposite  sides  must  resort  to  boats  or 
rafts.* 

EASTEEN  BORDER  CLIMATES 

On  windward  mountain  slopes  there  is  always  a  belt  of  maxi- 
mum precipitation   whose   elevation   and   width   vary   with   thel 
strength  of  the  wind,  with  the  temperature,  and  with  the  topog- 
raphy.   A  strong  and  constant  wind  will  produce  a  much  morej 
marked  concentration  of  the  rainfall.    The  belt  is  at  a  low  eleva- 
tion in  high  latitudes  and  at  a  high  elevation  in  low  latitudes,  with 
many  irregularities  of  position  dependent  upon  the  local  and  espe- 
cially the  minimum  winter  temperature.   _The  topographic  con- 
trols_areJmportant,  since  the  rain-compelling  elevation  may  scat- 
ter widely  the  localities  of  maximum  precipitation  or  concentrate   j 
them  within  extremely  narrow  limits.    The  human  effects  of  these  i 
climatic  conditions  are  manifold.     Wherever  the  heaviest  rains   ' 
are,  there,  too,  as  a  rule,  are  the  densest  forests  and  often  the 
most  valuable  kinds  of  trees.    If  the  general  climate  be  favorable 
and  the  region  lie  near  dense  and  advanced  populations,  exploita- 
tion of  the  forest  and  progress  of  the  people  will  go  hand  in  hand. 
If  the  region  be  remote  and  some  or  all  of  the  people  in  a  primi- 
tive state,  the  forest  may  hinder  communication  and  retard  devel- 
opment, especially  if  it  lie  in  a  hot  zone  where  the  natural  growth 
of  population  is  slow.   .    .    .   These  are  some  of  the  considerations 
we  shall  keep  in  mind  while  investigating  the  climate  of  the  east- 
ern border  of  the  Peruvian  Andes. 

The  belt  of  maximum  precipitation  on  the  eastern  border  of 
the  Andean  Cordillera  in  Peru  lies  between  4,000  and  10,000  feet. 
Judging  by  the  temporary  records  of  the  expedition  and  especially 


*  In  most  of  the  coast  towns  the  ford  or  ferry  is  an  important  institution  and  the 
chimiadores  or  haleadores  as  they  are  called  are  expert  at  their  trade:  they  know 
the  regime  of  the  rivers  to  a  nicety.  Several  settlements  owe  their  origin  to  the 
exigencies  of  transportation,  permanent  and  periodic;  thus  before  the  development  of 
its  irrigation  system  Camanfi,  according  to  General  Miller  (Memoirs,  London.  1829, 
Vol.  2,  p.  27),  was  a  hamlet  of  some  30  people  who  gained  their  livelihood  through 
ferrying  freight  and  passengers  across  the  ilajes  River. 


148 


THE  ANDES  OF  SOUTHERN  PERU 


by  the  types  of  forest  growth,  the  heaviest  rains  occur  around 
8,000  feet.  It  is  between  these  elevations  that  the  densest  part 
of  the  Peruvian  montana  (forest)  is  found.  The  cold  timber  line 
is  at  10,500  feet  with  exceptional  extensions  of  a  few  species  to 


ZONEOFLIGHT  RAIN  AND  LOCAL  SNOW    ZONE  OFMAXIMUM  RAINFALL 


DRY  AND  WET  SEASONS  SHARPLY 
MARKED  AND  EQUAL  IN  LENGTH 


;ONE  WELL-MARKED  SHORT  DRY 
iSEASON 


ZONE  OF  MODERATE  RAINFALL 
ONE  WELL-MARKED  LONG  DRY 
SEASON 


Fig.  93 a — Cloud  types  and  rainfall  belts  on  the  eastern  border  of  the  Peruvian  Andes 
in  the  dry  season,  southern  winter.  The  zone  of  maximum  rainfall  extends  approxi- 
mately from  4,000  to  10,000  feet  elevation. 

12,500  feet.  In  basins  or  deep  secluded  valleys  near  the  moun- 
tain border,  a  dry  timber  line  occurs  at  3,000  feet  with  many  varia- 
tions in  elevation  due  to  the  variable  declivity  and  exposure  of  the 
slopes  and  degree  of  seclusion  of  the  valleys.     Elsewhere,  the 


TRADES  FEEBLER ;  LOCAL  INFLU-  :  TRADES  REINFORCED  BY  STRONG  UP 
ENCES  STRONG  |  VALLEY  WINDS  BY  DAY  AND  NEUTRAL- 

^ .  i   IZED  BY  MODERATE  DOWN-VALLEY 


NORMAL  TRADES 


Fig.   9313 — Cloud   types  and   rainfall    bolts  on  the   castcni    border  of   tlio   Peruvian 
Andes  in  the  wet  season,  southern  summer. 

mountain  forest  passes  without  a  break  into  the  phiins  forest  with 
change  in  type  but  with  little  change  in  density.  The  procumbent 
and  suppressed  irecs  of  the  cold  liiiihei'  line  in  regions  of  heavy 
winter  snows  are  here  absent,  for  the  snows  rarely  reach  below 
14,000  feet  and  even  at  that  elevation  they  are  only  liglit  and  tem- 
porary. The  line  of  perpetual  snow  is  at  15,000  feet.  This 
permanent  gap  of  several  thousand  feet  vertical  elevation  between 
the  zone  of  snow  and  the  zone  of  forest  permits  the  full  extension 
of  many  pioneer  forest  species,  which  is  to  say,  tlieic  is  an  irregu- 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  149 

lar  development  of  the  cold  timber  line.  It  also  permits  the  full 
use  of  the  pasture  belt  above  the  timber  (Fig.  97),  hence  perma- 
nent habitations  exist  but  little  below  the  snowline  and  a  group 
of  distinctive  high-mountain  folk  enjoys  a  wide  distribution. 
There  is  a  seasonal  migration  here,  but  it  is  not  w^holesale ;  there 
are  pastures  snow-covered  in  the  southern  winter,  but,  instead  of 
the  complete  winter  burial  of  the  Alpine  meadows  of  our  western 
mountains,  we  have  here  only  a  buried  upper  fringe.  All  the  rest 
of  the  pasture  belt  is  open  for  stock  the  year  round. 

This  climatic  distinction  between  the  lofty  grazing  lands  of  the 
tropics  and  those  of  the  temperate  zones  is  far-reaching.  Our 
mountain  forests  are  not  utilized  from  above  but  from  below. 
Furthermore,  the  chief  ways  of  communication  lead  around  our 
forests,  or,  if  through  them,  only  for  the  purpose  of  putting  one 
population  group  in  closer  touch  with  another.  In  the  Peruvian 
Andes  the  largest  population  groups  live  above  the  forest,  not  be- 
low it  or  within  it.    It  must  be  and  is  exploited  from  above. 

Hence  railways  to  the  eastern  valleys  of  Peru  have  two  chief 
objects,  (1)  to  get  the  plantation  product  to  the  dense  populations 
above  the  forest  and  (2)  to  bring  timber  from  the  montana  to  the 
treeless  plateau.  The  mountain  prospector  is  always  near  a  habi- 
tation; the  rubber  prospector  goes  down  into  the  forested  valleys 
and  plains  far  from  habitations.  The  forest  separates  the  naviga- 
ble streams  from  the  chief  towns  of  the  plateau;  it  does  not  lead 
do^vn  to  rich  and  densely  populated  valley  floors. 

Students  in  eastern  Peru  should  find  it  a  little  difficult  to 
understand  poetical  allusions  to  silent  and  lonely  highlands  in  con- 
trast to  the  busy  life  of  the  valleys.  To  them  Shelley's  descrip- 
tion of  the  view  from  the  Euganean  Hills  of  northern  Italy, 

"  Beneath  is  spread  like  a  green  sea 
The  waveless  plain   of  Lombardy,   .    .    . 
Islanded  by  cities  fair," 

might  well  seem  to  refer  to  a  world  that  is  upside  down. 

There  is  much  variation  in  the  forest  tj^pes  between  the  moun- 
tains and  the  plains.     At  the  top  of  the  forest  zone  the  warm 


150  THE  ANDES  OF  SOUTHERN  PERU 

sunny  slopes  have  a  forest  cover;  the  shady  slopes  are  treeless. 
At  the  lower  edge  of  the  grassland,  only  the  shady  slopes  are  for- 
ested (Fig.  53B).  Cacti  of  arboreal  size  and  form  grow  on  the 
lofty  mountains  far  above  the  limits  of  the  true  forest;  they  also 
appear  at  3,000  feet  in  modified  form,  large,  rank,  soft-spined,  and 
in  dense  stands  on  the  semi-arid  valley  floors  below  the  dry  timber 
line.  Large  tracts  between  8,000  and  10,000  feet  are  covered  with 
a  forest  growth  distributed  by  species — here  a  dense  stand  of  one 
type  of  tree,  there  another.  This  is  the  most  accessible  part  of 
the  Peruvian  forest  and  along  the  larger  valleys  it  is  utilized  to 
some  extent.  The  number  of  species  is  more  limited,  however,  and 
the  best  timber  trees  are  lower  down.  Though  often  referred  to 
as  jungle,  the  lowlier  growths  at  the  upper  edge  of  the  forest  zone 
have  no  resemblance  to  the  true  jungle  that  crowds  the  lowland 
forest.  They  are  merely  an  undergrowth,  generally  open,  though 
in  some  places  dense.  They  are  nowhere  more  dense  than  many 
examples  from  New  England  or  the  West. 

Where  deep  valleys  occur  near  the  border  of  the  mountains 
there  is  a  semi-arid  climate  below  and  a  wet  climate  above,  with  a 
correspondingly  greater  number  of  species  within  short  distances 
of  each  other.  This  is  a  far  more  varied  forest  than  at  the  upper 
edge  of  the  timber  zone  or  down  on  the  monotonous  plains.  It 
has  a  higher  intrinsic  value  than  any  other.  That  part  of  it  be- 
tween the  Pongo  and  Yavero  (1,200  to  4,000  feet)  is  very  beauti- 
ful, with  little  undergrowth  except  a  light  ground-cover  of  ferns. 
The  trees  are  from  40  to  100  feet  in  height  with  an  average 
diameter  of  about  15  inches.  It  would  yield  from  3,000  to  5,000 
board  feet  per  acre  exclusive  of  the  palms.  There  are  very  few 
vines  suspended  from  the  forest  crown  and  the  trunks  run  clear 
from  30  to  GO  feet  above  the  ground.  Were  there  plenty  of  labor 
and  a  good  transportation  line,  these  stands  would  have  high  eco- 
nomic value.  Among  the  most  noteworthy  trees  are  the  soft  white 
cedar,  strong  and  light;  the  amarillo  and  the  sumbayllo,  very  dura- 
ble in  water;  the  black  nogal,  and  the  black  balsam,  straight  and 
easy  to  work;  the  heavy  yunquero,  which  turns  pink  when  dry; 
the  chunta  or  black  palm,  so  hard  and  straight  and  easy  to  split 


Fig.  94. 


Fig.  95. 


Fig.  94 — Cloud  belt  at  11,000  feet  in  the  Apurimac  Canyon  near  Incahuasi.  For  a 
regional  diagram  and  a  climatic  cross-section  see  Figs.  32  and  33. 

Fig.  95 — The  tropical  forest  near  Pabeilou  on  the  slopes  of  the  Urubamba  Valley. 
Elevation  3,000   feet    (915   ni.). 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  151 

that  wooden  nails  are  made  from  it;  and  tlie  rarer  sandy  matico, 
highly  prized  for  dug-out  canoes.  Also  from  the  chunta  palm,  hol- 
low except  for  a  few  central  fibers,  easily  removed,  pipes  are  made 
to  convey  water.  The  cocobolo  has  a  rich  brown  color  and  a 
glossy  surface  and  is  very  rare,  hence  is  much  sought  after  for 
use  in  furniture  making.  Most  of  these  woods  take  a  brilliant 
polish  and  exhibit  a  richness  and  depth  of  color  and  a  beauty  of 
grain  that  are  rare  among  our  northern  woods. 

The  plains  forest  northeast  of  the  mountains  is  in  the  zone  of 
moderate  rainfall  where  there  is  one  long  dry  season  and  one 
long  wet  season.  When  it  is  dry  the  daytime  temperatures  rise 
rapidly  to  such  high  levels  that  the  relative  humidity  of  the  air 
falls  below  50  per  cent  (Fig.  110).  The  effect  on  the  vegetation  is 
so  marked  that  many  plants  pass  into  a  distinctly  wilted  condi- 
tion. On  clear  days  the  rapid  fall  in  the  relative  humidity  is 
astonishing.  By  contrast  the  air  on  the  mountain  border  heats 
more  slowly  and  has  a  higher  relative  humidity,  because  clouds 
form  almost  constantly  in  the  ascending  air  currents  and  reflect 
and  absorb  a  large  part  of  the  heat  of  the  sun's  rays.  It  is  strik- 
ing to  find  large  tracts  of  cane  and  bamboo  on  the  sand  bars  and 
on  wet  shady  hillslopes  in  the  slope  belt,  and  to  pass  out  of  them 
in  going  to  the  plains  with  which  we  generally  associate  a  swamp 
vegetation.  They  exist  on  the  plains,  but  only  in  favored,  that  is 
to  say  wet,  spots.  Larger  and  more  typical  tracts  grow  farther 
north  where  the  heavier  rains  of  the  Amazon  basin  fall. 

The  floods  of  the  wet  tropical  season  also  have  a  restricting  in- 
fluence upon  the  tropical  forest.  They  deliver  such  vast  quantities 
of  w^ater  to  the  low-gradient  lowland  streams  that  the  plains 
rivers  double,  even  treble,  their  width  and  huge  pools  and  even 
temporary  lakes  form  in  the  shallow  depressions  back  of  the 
natural  levees.  Of  trees  in  the  flooded  areas  there  are  only  those 
few  species  that  can  grow  standing  in  water  several  months  each 
year.  There  are  also  cane  and  bamboo,  ferns  in  unlimited  num- 
bers, and  a  dense  growth  of  jungle.  These  are  the  haunts  of  the 
peccary,  the  red  forest  deer,  and  the  jungle  cat.  Except  along  the 
narrow  and  tortuous  animal  trails  the  country  is  quite  impassa- 


152  THE  ANDES  OF  SOUTHERN  PERU 

ble.  Thus  for  the  sturdiest  and  most  useful  forest  growth  the 
one-wet-one-dry  season  zone  of  the  plains  has  alternately  too 
much  and  too  little  water.  The  rubber  tree  is  most  tolerant  toward 
these  conditions.  Some  of  the  best  stands  of  rubber  trees  in  Ama- 
zonia are  in  the  southwestern  part  of  the  basin  of  eastern  Peru 
and  Bolivia,  where  there  is  the  most  typical  development  of  the 
habitat  marked  by  the  seasonal  alternation  of  floods  and  high 
temperatures. 

When  tropical  agriculture  is  extended  to  the  plains  the  long 
dry  season  will  be  found  greatly  to  favor  it.  The  southwest- 
ern quadrant  of  the  Amazon  basin,  above  referred  to,  is  the 
best  agricultural  area  within  it .  The  northern  limits  of  the 
tract  are  only  a  little  beyond  the  Pongo.  Thence  northward  the 
climate  becomes  wetter.  Indeed  the  best  tracts  of  all  extend  from 
Bolivia  only  a  little  w^ay  into  southeastern  Peru,  and  are  coinci- 
dent with  the  patchy  grasslands  that  are  there  interspersed  with 
belts  of  woodland  and  forest.  Sugar-cane  is  favored  by  a  climate 
that  permits  rapid  growth  with  a  heavy  rainfall  and  a  dry  season 
is  required  for  quality  and  for  the  harvest.  Rice  and  a  multitude 
of  vegetable  crops  are  also  well  suited  to  this  type  of  climate. 
Even  corn  can  be  grown  in  large  quantities. 

At  the  present  time  tropical  agriculture  is  almost  wholly  con- 
fined to  the  mountain  valleys.  The  reasons  are  not  wholly  cli- 
matic, as  the  above  enumeration  of  the  advantages  of  the  plains 
suggests.  The  consuming  centers  are  on  the  plateau  toward  the 
west  and  limitation  to  mule  pack  transport  always  makes  distance 
in  a  rough  country  a  very  serious  problem.  The  valleys  combine 
witli  the  advantage  of  a  short  haul  a  climate  astonishingly  like  the 
one  just  descri])od.  Tn  fact  it  is  oven  more  extreme  in  its  seasonal 
contrasts.  Tlie  exi)I;ni;i11()ii  is  dependent  ii])()ii  precisely  the  same 
])iliici|)l('s  we  liave  irHlicrfo  ('iii))l()y(Ml.  M'lic  front  range  of  the 
Andes  and  tlie  course  of  llie  Urubaiiiba  rini  i)ai-:illol  for  some  dis- 
tance. Fiirtlif-r,  llic  front  range  is  in  many  ])laces  soniowliat 
higher  llian  tlie  mountain  s[)urs  and  kno})s  directly  beliind  it. 
Even  when  these  relations  are  reversed  the  front  range  still  acts 
as  a  barrier  to  the  rains  for  all  llic  deep  valleys  behind  it  whose 


CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  153 

courses  are  not  directly  toward  the  plains.  Thus,  one  of  the 
largest  valleys  in  Peru,  the  Urubamba,  drops  to  3,400  feet  at 
Santa  Ana  and  to  2,000  feet  at  Rosalina,  well  within  the  eastern 
scarp  of  the  Andes.  The  mountains  immediately  about  it  are  from 
6,000  to  10,000  feet  high.  The  result  is  a  deep  semi-arid  pocket 
with  only  a  patchy  forest  (Fig.  54,  p.  79).'  In  places  the  degree 
of  seclusion  from  the  wind  is  so  great  that  the  scrub,  cacti,  and 
irrigation  remind  one  strongly  of  the  desert  on  the  border 
of  an  oasis,  only  here  the  transition  is  toward  forests  instead 
of  barren  wastes.  The  dense  forest,  or  montana,  growls  in  the 
zon^  of  clouds  and  maximum  precipitation  between  4,000  and 
lOjOOO  feet.  At  the  lower  limit  it  descends  a  thousand  feet 
farther  on  shady  slopes  than  it  does  on  sunny  slopes.  The 
continuous  forest  is  so  closely  restricted  to  the  cloud  belt  that 
in  Fig.  99  the  two  limits  may  be  seen  in  one  photograph.  All 
these  sharply  defined  limits  and  contrasts  are  due  to  the  fact 
that  the  broad  valley,  discharging  through  a  narrow  and  remote 
gorge,  is  really  to  leeward  of  all  the  mountains  around  it.  It 
is  like  a  real  desert  basin  except  in  a  lesser  degree  of  exclusion 
from  the  rains.  If  it  were  narrow  and  small  the  rains  formed  on 
the  surrounding  heights  would  be  carried  over  into  it.  Rain  on 
the  hills  and  sunshine  in  the  valley  is  actually  the  day-by-day 
weather  of  the  dry  season.  In  the  wet  season  the  sky  is  overcast, 
the  rains  are  general,  though  lighter  in  the  valley  pocket,  and 
plants  there  have  then  their  season  of  most  rapid  growth.  The 
dry  season  brings  plants  to  maturity  and  is  the  time  of  harvest. 
Hence  sugar  and  cacao  plantations  on  a  large  scale,  hence  a 
varied  life  in  a  restricted  area,  hence  a  distinct  geographic  prov- 
ince unique  in  South  America. 

INTER-AlSTDEAISr    VALLEY    CLIMATES 

Not  all  the  deep  Andean  valleys  lie  on  or  near  the  eastern 
border.    Some,  like  the  Apurimac  and  the  Maranon,  extend  well 

°A  dry  pocket  in  the  Hiiallaga  basin  between  6°  and  7°  S.  is  described  by  Spruce 
(Notes  of  a  Botanist  on  the  Amazon  and  Andes,  2  vols.,  London,  lOOS).  Tarapoto  at 
an  elevation  of  1,500  feet  above  sea  level,  encircled  by  hills  rising  2,000  to  3,000  feet 
higher,  rarely  experiences  hea^'y  rain  though  rain  falls  frequently  on  the  hills. 


154  THE  ANDES  OF  SOUTHERN  PERU 

into  the  interior  of  the  Cordillera.  Besides  these  deep  remote  val- 
leys with  their  distinct  climatic  belts  are  basins,  most  of  them  with 
outlets  to  the  sea — broad  structural  depressions  occurring  in 
some  cases  along  large  and  in  others  along  small  drainage  lines. 
The  Cuzco  basin  at  11,000  feet  and  the  Abancay  basin  at  6,000  to 
8,000  feet  are  typical.  Both  have  abrupt  borders,  narrow  outlets, 
large  bordering  alluvial  fans,  and  fertile  irrigable  soil.  Their  dif- 
ference of  elevation  occurs  at  a  critical  level.  Corn  will  ripen  in 
the  Cuzco  basin,  but  cane  will  not.  Barley,  wheat,  and  potatoes 
are  the  staple  crops  in  the  one;  sugar-cane,  alfalfa,  and  fruit  in 
the  other.  Since  both  are  bordered  by  high  pastures  and  by  min- 
eralized rocks,  the  deeper  Abancay  basin  is  more  varied.  If  it 
were  not  so  difficult  to  get  its  products  to  market  by  reason  of  its 
inaccessibility,  the  Abancay  basin  would  be  the  more  important. 
In  both  areas  there  is  less  rainfall  on  the  basin  floor  than  on  the 
surrounding  hills  and  mountains,  and  irrigation  is  practised,  but 
the  deeper  drier  basin  is  the  more  dependent  upon  it.  Many  small 
high  basins  are  only  within  the  limits  of  potato  cultivation.  They 
also  receive  proportionately  more  rain.  Hence  irrigation  is  un- 
necessary. According  as  the  various  basins  take  in  one  or  another 
of  the  different  product  levels  (Fig.  35)  their  life  is  meager  and 
unimportant  or  rich  and  interesting. 

The  deep-valley  type  of  climate  has  the  basin  factors  more 
strongly  developed.  Below  the  Canyon  of  Choqquequirau,  a  topo- 
graphic feature  comparable  with  the  Canyon  of  Torontoy,  the 
Apurimac  descends  to  3,000  feet,  broadens  to  several  miles,  and 
has  large  alluvial  fans  built  into  it.  Its  floor  is  really  arid,  with 
naked  gravel  and  rock,  cacti  stands,  and  gnarled  shrubs  as  the 
cliief  elements  of  the  landscape.  Moreover  the  lower  part  of  the 
valley  is  the  steeper.  A  former  erosion  level  is  indicated  in  Fig. 
125.  When  it  was  in  existence  the  slopes  were  more  moderate  than 
now  and  the  valley  broad  and  open.  Thereupon  came  uplift  and 
the  incision  of  the  stream  to  its  present  level.  As  a  result,  a  steep 
canyon  was  cut  in  tlie  floor  of  a  mature  valley.  Hence  the  slopes 
are  in  a  relation  unlike  that  of  most  of  the  slopes  in  our  most 
familiar  landscapes.     The  gentle  slopes  arc  above,  the  steep  be- 


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CLIMATOLOGY  OF  THE  PERUVIAN  ANDES  155 

low.     The  break  between  the  two,  a  topographic  unconformity, 
may  be  distinctly  traced. 

Combined  with  these  topographic  features  are  certain  climatic 
features  of  equal  precision.  Between  7,000  and  13,000  feet  is  a 
zone  of  clouds  oftentimes  marked  out  as  distinctly  as  the  belt  of 
fog  on  the  Peruvian  coast.**  Earely  does  it  extend  across  the  val- 
ley. Generally  it  hangs  as  a  white  belt  on  the  opposite  walls. 
When  the  up-valley  winds  of  day  begin  to  blow  it  drifts  up-valley, 
oftentimes  to  be  dissolved  as  it  strikes  the  warmer  slopes  of  the 
upper  valley,  just  as  its  settling  under  surface  is  constantly  being 
dissolved  in  the  warm  dry  air  of  the  valley  floor.  Where  the  pre- 
cipitation is  heaviest  there  is  a  belt  of  woodland — dark,  twisted 
trees,  moss-draped,  wet — a  Druid  forest.  Below  and  above  the/ 
woodland  are  grassy  slopes.  At  Incahuasi  a  spur  runs  out  and 
down  until  at  last  it  terminates  between  two  deep  canyons.  No 
ordinary  wells  could  be  successful.  The  ground  water  must  be 
a  thousand  feet  down,  so  a  canal,  a  tiny  thing  only  a  few  inches 
wide  and  deep,  has  been  cut  away  up  to  a  w^oodland  stream. 
Thence  the  water  is  carried  down  by  a  contour-like  course  out  of 
the  woodland  into  the  pasture,  and  so  down  to  the  narrow  part  of 
the  spur  where  there  is  pasture  but  no  springs  or  streams. 

Corn  fields  surround  the  few  scattered  habitations  that  have 
been  built  just  above  the  break  or  shoulder  on  the  valley  wall 
where  the  woodland  terminates,  and  there  are  fine  grazing  lands. 
The  trails  follow  the  upper  slopes  whose  gentler  contours  permit 
a  certain  liberty  of  movement.  Then  the  way  plunges  downward 
over  a  staircase  trail,  over  steep  boulder-strewn  slopes  to  the  arid 
floor  of  a  tributary  where  nature  has  built  a  graded  route.  And 
so  to  the  still  more  arid  floor  of  the  main  valley,  where  the  ample 
and  moderate  slopes  of  the  alluvial  fans  with  their  mountain 
streams  permit  plantation  agriculture  again  to  come  in. 

To  these  three  climates,  the  western  border  type,  the  eastern 

°  Speaking  of  C6mas  situated  at  the  headwaters  of  a  source  of  the  Perene  amidst 
a  multitude  of  quebradas  Raimondi  (op.  cit.,  p.  109)  says  it  "might  properly  be  called 
the  town  of  the  clouds,  for  there  is  not  a  day  during  the  year,  at  any  rate  towards 
the  evening,  when  the  town  is  not  enveloped  in  a  mist  sufficient  to  hide  everything 
from  view." 


156  THE  ANDES  OF  SOUTHERN  PERU 

border  type,  and  the  inter- Andean  type,  we  have  given  chief  at- 
tention because  they  have  the  most  important  human  relations. 
The  statistical  records  of  the  expedition  as  shoAvn  in  the  curves 
and  the  discussion  that  accompanies  them  give  attention  to  those 
climatic  features  that  are  of  theoretical  rather  than  practical  inter- 
est, and  are  largely  concerned  with  the  conventional  expression 
of  the  facts  of  weather  and  climate.  They  are  therefore  com- 
bined in  the  following  chapter  which  is  devoted  chiefly  to  a  tech- 
nical discussion  of  the  meteorology  as  distinguished  from  the 
climatology  of  the  Peruvian  Andes. 


CHAPTER  X 
METEOROLOGICAL  RECORDS  FROM  THE  PERUVIAN  ANDES 

Introduction 

The  data  in  this  chapter,  on  the  weather  and  climate  of  the 
Peruvian  Andes,  were  gathered  under  the  usual  difficulties  that  ac- 
company the  collection  of  records  at  camps  scarcely  ever  pitched 
at  the  same  elevation  or  with  the  same  exposure  two  days  in  suc- 
cession. Some  of  them,  and  I  may  add,  the  best,  were  contributed 
by  volunteer  observers  at  fixed  stations.  The  observations  are 
not  confined  to  the  field  of  the  Yale  Peruvian  Expedition  of 
1911,  but  include  also  observations  from  Professor  Hiram  Bing- 
ham's Expeditions  of  1912  and  1914-15,  together  with  data  from 
the  Yale  South  American  Expedition  of  1907.  In  addition  I 
have  used  observations  supplied  by  the  Morococha  Mining  Com- 
pany through  J.  P.  Little.  Some  hitherto  unpublished  observa- 
tions from  Cochabamba,  Bolivia,  gathered  by  Herr  Kriiger  at  con- 
siderable expense  of  money  for  instruments  and  of  time  from  a 
large  business,  are  also  included,  and  he  deserves  the  more  credit 
for  his  generous  gift  of  these  data  since  they  were  collected  for 
scientific  purposes  only  and  not  in  connection  with  enterprises  in 
which  they  might  be  of  pecuniary  value.  My  only  excuse  to  Herr 
Kriiger  for  this  long  delay  in  publication  (they  were  put  into  my 
hands  in  1907)  is  that  I  have  wanted  to  publish  his  data  in  a  digni- 
fied form  and  also  to  use  them  for  comparison  with  the  data  of 
other  climatic  provinces. 

A  further  word  to  the  reader  seems  necessary  before  he  ex- 
amines the  following  curves  and  tables.  It  would  be  somewhat 
audacious  to  assume  that  these  short-term  records  have  far-reach- 
ing importance.  Much  of  their  value  lies  in  their  organization 
with  respect  to  the  data  already  published  on  the  climate  of  Peru. 
But  since  this  would  require  a  delay  of  several  j^ears  in  their  pub- 
lication it  seems  better  to  present  them  now  in  their  simplest 
form.    After  all,  the  professional  climatologist,  to  whom  they  are 

157 


158 


THE  ANDES  OF  SOUTHERN  PERU 


chiefly  of  interest,  scarcely  needs  to  have  such  organization  sup- 
plied to  him.  Then,  too,  we  hope  that  there  will  become  available 
in  the  next  ten  or  fifteen  years  a  vastly  larger  body  of  climato- 
logical  facts  from  this  region.  When  these  have  been  collected 
we  may  look  forward  to  a  volume  or  a  series  of  volumes  on  the 
** Climate  of  Peru,"  with  full  statistical  tables  and  a  complete  dis- 
cussion of  them.  That  would  seem  to  be  the  best  time  for  the  re- 
production of  the  detailed  statistics  now  on  hand.  It  is  only  nec- 
essary that  there  shall  be  sufficient  analysis  of  the  data  from  time 
to  time  to  give  a  general  idea  of  their  character  and  to  indicate 
in  what  way  the  scope  of  the  observations  might  profitably  be  ex- 
tended. I  have,  therefore,  taken  from  the  available  facts  only 
such  as  seem  to  me  of  the  most  importance  because  of  their  un- 
usual character  or  their  special  relations  to  the  boundaries  of 
plant  provinces  or  of  the  so-called  ''natural  regions"  of 
geography. 

Machu  Picchu^ 
The  following  observations  are  of  special  interest  in  that  they 
illustrate  the  weather  during  the  southern  winter  and  spring  at 
the  famous  ruins  of  Machu  Picchu  in  the  Canyon  of  Torontoy. 
The  elevation  is  8,500  feet.  The  period  they  cover  is  too  short  to 
give  more  than  a  hint  of  the  climate  or  of  the  weather  for  the 
year.  It  extends  from  August  20,  1912,  to  November  6,  1912  (79 
days). 

ANALYTICAL  TABLE  OF  WIND  DIRECTIONS,  MACHU  PICCHU,  1912 


Number  of  ObservationB 

Direction  of  wind 

AiiR.  80         —            Sept.  80 
7  a.  in.        1  p.  m.        7  p.  m. 

Oct.  1                —              Nov.  0 
7  a.'ni.           1  ]).  ni.          7  )).  ni. 

N 

5             2             5 

n         10         14 

—  1              2 

—  —              1 

—  —              1 
4              2              1 
G              3              3 
8              7              G 

—  —              2 

2            —            — 

N    "W        

4              G            11 

w        

2              2              4 

s    \v                 

1               1               G 

s       

2 

SI-:       

—            —              3 

H            

12              4              4 

N  !•:   

4              13 

CALM       

5              3              3 

» Observer:  E.  C.  Erdis  of  the  1912  and  1014-15  Expeditions. 


METEOROLOGICAL  RECORDS 


159 


Direction  of  wind 


N.  ... 
N.  W. 
W.  ... 

s.  w. 

s 

S.  E.  . 
E 

N.  E.  . 
CALM 


Percentages  of  Total  Observations  ' 


Aug.  20 
7  a.  m. 


1  p.  m. 


Sept.  30 
7  p.  m. 


15.6 
28.1 


12.5 

18.8 
25.0 


8.0 

40.0 

4.0 


8.0 
12.0 
28.0 


14.2 
40.0 
5.7 
2.8 
2.8 
2.8 
8.6 
17.1 
5.7 


Oct.  1 

— 

Nov.  6 

7  a.  m. 

1  p.  m. 

7  p.  m. 

6.7 
13.3 

35.3 

30.7 

6.7 

11.8 

11.1 

3.3 

5.9 

16.7 
5.5 

40.0 
13.3 
16.7 


23.5 

5.9 

17.6 


11.1 
8.3 
8.3 


The  high  percentage  of  northwest  winds  during  afternoon 
hours  is  due  to  the  up-valley  movement  of  the  air  common  to  almost 
all  mountain  borders.  The  air  over  a  mountain  slope  is  heated 
more  than  the  free  air  at  the  same  elevation  over  the  plains  (or 

N  ,  N  _  N 


7  a.m 


1  p.m. 


7  p.m 


Fig.  100 — Wind  roses  for  Macliu  riccliu,  August  20  to  November  6,  1912. 

lower  valley) ;  hence  a  barometric  gradient  towards  the  mountain 
becomes  established.  At  Machu  Picchu  the  Canj^on  of  Torontoy 
trends  northwest,  making  there  a  sharp  turn  from  an  equally 
sharp  northeast  bend  directly  upstream.  The  easterly  components 
are  unrelated  to  the  topography.  They  represent  the  trades.  If 
a  wind  rose  were  made  for  still  earlier  morning  hours  these  winds 
would  be  more  faithfully  represented.  That  an  easterly  and 
northeasterly  rather  than  a  southeasterly  direction  should  be  as- 
sumed by  the  trades  is  not  difficult  to  believe  when  we  consider 
the  trend  of  the  Cordillera — southeast  to  northwest.    The  observa- 


Percentages  given  because  the  number  of  observations  varies. 


160 


THE  ANDES  OF  SOUTHERN  PERU 


tions  from  here  down  to  the  plains  all  show  that  there  is  a  distinct 
change  in  wind  direction  in  sjTnpathy  with  the  larger  features  of 
the  topography,  especially  the  deep  valleys  and  canyons,  the  trades 
coming  in  from  the  northeast. 

CLOUDINESS 

It  will  be  seen  that  the  sky  was  overcast  or  a  fog  lay  in  the 
valley  53  per  cent  of  the  time  at  early  morning  hours.  Even  at 
noon  the  sky  was  at  no  time  clear,  and  it  was  more  than  50  per 
cent  clear  only  18  per  cent  of  the  time.  Yet  this  is  the  so-called 
**dry"  season  of  the  valleys  of  the  eastern  Andes.  The  rainfall 
record  is  in  close  sympathy.  In  the  79  days '  observations  rain  is 
recorded  on  50  days  with  a  greater  proportion  from  mid-Septem- 
ber to  the  end  of  the  period  (November  6),  a  distinct  transition 
toward  the  wet  period  that  extends  from  December  to  May.  The 
approximate  distribution  of  the  rains  by  hours  of  observation 
(7  A.  M.,  1  p.  M.,  7  p.  M.)  was  in  the  ratio  4:3:6.  Also  the  greatest 
number  of  heavy  showers  as  well  as  the  greatest  number  of 
showers  took  place  in  the  evening.  The  rainfall  was  apparently 
/unrelated  to  wind  direction  in  the  immediate  locality,  though  un- 
doubtedly associated  with  the  regional  movement  of  the  moist 
[plains  air  toward  the  mountains.  All  these  facts  regarding 
clouds  and  rain  plainly  show  the  location  of  the  place  in  the  belt 
of  maximum  precipitation.  There  is,  therefore,  a  heavy  cover  of 
vegetation.  While  the  situation  is  admirable  for  defence,  the 
murky  skies  and  frequent  fogs  somewhat  offset  its  topographic 
surroundings  as  a  lookout. 

ANALYTICAL   TABLE   OF   THE   STATE   OF   THE   SKY,    MACHU   PICCIIU,    1912 


Mornlbi; 

TotJil 

Noon 

Total 

KvcninK 

Total 

Ang.' 
Sept. 

3.0 

12.0 

4.0 

G.O 
3.0 

Oct.. 
Nov. 

14.0 
3.0 

10.0 
4.0 
1  0 

Days 

* 

Aug.. 
Sept. 

Ocl.. 
Nov. 

Dayn 

* 

Aug.. 
Sept. 

Oct.- 
Nov. 

Dnyn 

% 

FofTto'    

Ovorcast     

17.0 
1.'').0 

28.4 

1.0 
0.0 
9.0 
5.0 
0.0 

8.0 

7.0 
2.0 
0.0 

1.0 
14.0 

in.o 

7.0 
0.0 

2.G 
30.8 
42.2 
18.4 

0.0 

1.0 

13.0 

8.0 

9.0 
3.0 

2.0 

11.0 

15.0 

4.0 

3.0 

3.0 
24.0 
23.0 
13.0 

G.O 

4.3 

34  8 

.^.0-100%  clr.u.ly  .  .  .  . 

0-50%  cloudy 

Clear   

14.0  23.3 

IO.OIIG.7 

4.0 1   6.6 

.33.3 

18.8 
88 

METEOROLOGICAL  RECORDS 


161 


Santa  Lucia  ^ 
Santa  Lucia  is  a  mining  center  in  the  province  of  Puno  (16° 
S.),  at  the  head  of  a  valley  here  running  northeast  towards  Lake 
Titicaca.  Its  elevation,  15v500  feet  above  sea  level,  confers  on  it 
unusual  interest  as  a  meteorological  station.  A  thermograph  has 
been  installed  which  enables  a  closer  study  of  the  temperature  to  be 
made  than  in  the  case  of  the  other  stations.  It  is  unfortunate,  how- 
ever, that  the  observations  upon  clouds,  wind  directions,  etc.,  should 
not  have  been  taken  at  regular  hours.  The  time  ranges  from  8.30 
to  11.30  for  morning  hours  and  from  2.30  to  5.30  for  afternoon. 
The  observations  cover  portions  of  the  years  1913  and  1914. 


TEMPERATURE 

Perhaps  the  most  striking  features  of  the  w^eather  of  Santa 
Lucia  are  the  highly  regular  changes  of  temperature  from  night 
to  day  or  the  uniformly  great  diurnal  range  and  the  small  dif- 
ferences of  temperature  from  day  to  day  or  the  low  diurnal 
variability.  For  the  whole  period  of  nearly  a  year  the  diurnal 
variability  never  exceeds  9.5°  F.  (5.3°  C.)  and  for  days  at  a  time 
it  does  not  exceed  2-3°  F.  (1.1°-1.7°  C).  The  most  frequent  varia- 
tion, occurring  on  71  per  cent  of  the  total  number  of  days,  is  from 
0-3°  F.,  and  the  mean  for  the  year  gives  the  low  variability  of 
1.9°  F.  (1.06^  C).  These  facts,  illustrative  of  a  type  of  weather 
comparable  in  uniformity  with  low  stations  on  the  Amazon  plains, 
are  shown  in  the  table  following  as  well  as  in  the  accompanying 
curves. 

FREQUENCY  OF  THE  DIURNAL  VARIABILITY,  SANTA  LUCIA,   1913-1-1 


Degrees  F. 

May 

June 

July 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

Jan. 

Feb. 

March 

Total  No. 
of  days 

0 

— 

2 

6 

3 

4 

G 

2 



1 



2 

26 

0-1 

2 

7 

7 

5 

6 

4 

8 

12 

14 

9 

5 

79 

1-2 

11 

5 

7 

11 

7 

8 

5 

5 

4 

9 

13 

85 

2-3 

2 

8 

8 

9 

3 

7 

7 

5 

5 

4 

G 

64 

3-4 

4 

4 

2 

1 

4 

1 

3 

6 

2 

4 

2 

33 

4-5 

1 

3 

1 

— 

2 

1 

3 

— 

2 

1 

1 

15 

Over  5 

— 

1 

— 

2 

4 

4 

2 

2 

3 

1 

— 

19 

Days  pel 

20 

30 

31 

31 

30 

31 

30 

30 

31 

28 

29 

321 

month 

'Observer:   Seuor  Valdivia.     For  location  of  Santa  Lucia  see  Fisr.  66. 


162  THE  ANDES  OF  SOUTHERN  PERU 

If  we  take  the  means  of  the  diurnal  variations  by  months  we 
have  a  still  more  striking  curve  showing  how  little  change  there 
is  between  successive  days.    June  and  December  are  marked  by 
humps  in  the  curve.     They  are  the  months  of  extreme  weather 
when  for  several  weeks  the  temperatures  drop  to  their  lowest  or 
climb  to  their  highest  levels.     Moreover,  there  is  at  these  lofty 
stations  no  pronounced  lag  of  the  maximum  and  minimum  tem- 
peratures for  the  year  behind  the  times  of  greatest  and  least  heat- 
ing such  as  we  have  at  lower  levels  in  the  temperate  zone.    Thus 
we  have  the  highest  temperature  for  the  year  on  December  2, 
70.4°  F.  (21.3°  C),  the  lowest  on  June  3,  0.2°  F.  (—17.7°  C).    The 
daily  maxima  and  minima  have  the  same  characteristic.    Radiation 
is  active  in  the  thin  air  of  high  stations  and  there  is  a  very 
direct  relation  between  the  times  of  greatest  heat  received  and 
greatest  heat  contained.    The  process  is  seen  at  its  best  immedi- 
ately after  the  sun  is  obscured  by  clouds.    In  five  minutes  I  have 
obser^^ed  the  temperature  drop  20°  F.   (11.1°  C)   at  1G,000  feet 
(4,877  m.) ;  and  a  drop  of  10'  F.  (5.6°  C.)  is  common  anywhere 
above  14,000  feet  (4,267  m.).    In  the  curves  of  daily  maximum  and 
minimum  temperatures  we  have  clearly  brouglit  out  the  uniform- 
ity with  which  the  maxima  of  high-level  stations  rise  to  a  mean 
level  during  the  winter  months"  (May- August).    Only  at  long  in- 
tervals is  there  a  short  series  of  cloudy  days  when  the  maximum 
is  10''-12°  F.   (5.6°-6.7'  C.)   below  the  normal  and  the  minimum 
stands  at  abnormally  high  levels.     Since  clouds  form  at  night 
in    quite    variable    amounts— in   contrast    to    the    nearly    cloud- 
less days— there  is  a  far  greater  variability  among  the  minimum 
temperaturos.      Indeed    the    variability    of    the    winter    minima 
is  greater  lliaii   lliat  of  the  summer  minima,  for   at  the   latter 
season  the  nightly  cloud  cover  imposes  much  more  stal)lo  atmos- 
pheric   temperatures.      The    summer    maxima    liavc    a    greater 
degree   of  variability.     Several  clear  days   in   succession   allow 
the    temperature    to    rise    from    r)°-10"    F.    (2.8°-r).6°    C.)    above 
the    wiiitor    maxima.       P.iil     such    extremes    are    rather    strictly 
confined    t(;    tiie   licjiglit   of    the    summer   season— December   and 
January.     For  the  rest  of  the   summer  the  maxima  rise   only 


METEOROLOGICAL  RECORDS  163 

a  few  degrees  above  those  of  the  winter.  This  feature  of  the 
climate  combines  with  a  December  maximum  of  rainfall  to  limit 
the  period  of  most  rapid  plant  growth  to  two  months.  Bar- 
ley sown  in  late  November  could  scarcely  mature  by  the  end  of 
January,  even  if  growing  on  the  Argentine  plains  and  much  less 
at  an  elevation  which  carries  the  night  temperatures  below  freez- 
ing at  least  once  a  week  and  where  the  mean  temperature  hovers 
about  47°  F.  (8.3°  C).  The  proper  conditions  for  barley  growing 
are  not  encountered  above  13,000  to  13,500  feet  and  the  farmer 
cannot  be  certain  that  it  will  ripen  above  32,500  feet  in  the  lati- 
tude of  Santa  Lucia. 

The  curve  of  mean  monthly  temperatures  expresses  a  fact  of 
great  importance  in  the  plant  growth  at  high  situations  in  the 
Andes — the  sharp  break  between  the  winter  and  summer  seasons. 
There  are  no  real  spring  and  autumn  seasons.  This  is  especially 
well  shown  in  the  curve  for  non-periodic  mean  monthly  range  of 
temperature  for  the  month  of  October.  During  the  half  of  the 
year  that  the  sun  is  in  the  southern  hemisphere  the  sun's  noon- 
day rays  strike  Santa  Lucia  at  an  angle  that  varies  between  0°  and 
16°  from  the  vertical.  The  days  and  nights  are  of  almost  equal 
length  and  though  there  is  rapid  radiation  at  night  there  is  also 
rapid  insolation  by  day.  When  the  sun  is  in  the  northern  hemi- 
sphere the  days  are  shortened  from  one  to  two  hours  and  the  angle 
of  insolation  decreased,  whence  the  total  amount  of  heat  received 
is  so  diminished  that  the  mean  monthly  temperature  lies  only  a 
little  above  freezing  point.  In  winter  the  quiet  pools  beside  the 
springs  freeze  over  long  before  dark  as  the  hill  shadows  grow 
down  into  the  high-level  valleys,  and  by  morning  ice  also  covers 
the  brooks  and  marshes.  Yet  the  sun  and  wind-cured  ichu  grass 
lives  here,  pale  green  in  summer,  straw-yellow  in  winter.  The 
tola  bush  also  grows  rather  abundantly.  But  we  are  almost 
at  the  upper  limit  of  the  finer  grasses  and  a  few  hundred  feet 
higher  carries  one  into  the  realm  of  the  snowline  vegetation, 
mosses  and  lichens  and  a  few  sturdy  flowering  plants. 

For  convenience  in  future  comparative  studies  the  absolute 
extremes  are  arranged  in  the  following  table: 


164  THE  ANDES  OF  SOUTHERN  PERU 

ABSOLUTE  MONTHLY  EXTREMES,   SANTA  LUCIA.,   1913-14 


Date 

Iligbest 

Lowest 

Date 

May*   (12) 

62°  F. 

9°F. 

May  (25,  26) 

June  (4  days) 

60°  F. 

0.2°  F. 

June  (3) 

July  (4  days,  31) 

60°  F. 

5°F. 

July  (S) 

Aug.  (8,  26) 

62°  F. 

4°F. 

Aug.   (4,  5) 

Sept.  (several  days) 

62°  F. 

7°F. 

Sept.  (4  days) 

Oct.   (24) 

63°  F. 

10°  F. 

Oct.  (12,  13) 

Nov.  (11)  ' 

63°  F. 

24.0°  F. 

Nov.  (29) 

Dec.  (2) 

70.4°  F. 

22.2°  F. 

Dec.  (14) 

Jan.   (19) 

69.5°  F. 

26.5°  F. 

Jan.  (3,  15) 

Feb.   (16,18) 

63.2°  F. 

30.5°  F. 

Feb.  (23) 

March  (8) 

68.4°  F. 

28.5°  F. 

March  (6) 

RAINFALL 

The  rainfall  record  for  Santa  Lucia  is  for  the  year  beginning 
November,  1913.  For  this  period  the  precipitation  amounts  to 
24.9  inches  of  which  over  85  per  cent  fell  in  the  rainy  season  from 
November  to  March.  Most  of  the  rain  fell  during  the  violent  after- 
noon tempests  that  characterize  the  summer  of  these  high  alti- 
tudes. 

The  rainfall  of  Santa  Lucia  for  this  first  year  of  record  ap- 
proximates closely  to  the  yearly  mean  of  23.8  inches  for  the  sta- 
tion of  Caylloma  in  the  adjacent  province  of  that  name.  Caylloma 
is  the  center  of  a  mining  district  essentially  similar  to  Santa 
Lucia  though  the  elevation  of  its  meteorological  station,  14,196 
feet  (4,330  m.),  is  lower.  It  is  one  of  the  few  Peruvian  stations 
for  which  a  comparatively  long  series  of  records  is  available.  The 
Boletin  de  la  Sociedad  Geogrdfica  de  Lima "  contains  a  resume  of 
r;iinfall  and  temperature  for  seven  years,  1896-7  to  1902-3.  Later 
data  may  be  found  iu  su])sequent  volumes  of  the  same  publication 
but  they  have  not  been  summarized  or  in  any  way  prepared  for 
analysis  and  they  contain  several  typ()grai)hical  errors.  A  graphic 
representation  of  the  inouilily  rainfall  for  the  earlier  jx'riod  is 
here   reproduced   from    llic   liolrf/in   de   minas   del   Peril.''     The 

*  Observations  began  on  May  12. 

'  I'or  tlm  fiTHt  luilf  of  tlio  month  only;  no  rrcord  for  the  Bocond  lialf. 

•  Holetfn  dp  la  Sociedsul  Oeogrftflra  d<'  Lima,  Vol.  13,  pp.  .IT-'t^HO,  Litii.i,  lOO.T. 

'  Holctfn  del  Cuorpo  do  IngmicroH  de  Minas  del  I'erri,  No.  .'M,  Lima,  lOOf),  also 
reproduced  in  No.  45,  1906. 


METEOROLOGICAL  RECORDS 


165 


IN. 

12- 


--200 


jj 


MM.      IN. 
12- 


-250 


■150  G" 


100  4- 


=  -60 


L-Q Q_ 


MM, 


-250 


-200 


=  -100 


=  -50 


n.  d.  j.  e.  m.  a.  m.  j.  j.  a.  s.  o. 
Fig.   102. 


J.   F.  M.  A.  M.  J.  J.  A.  S.  O.  N.  D. 

Fig.   103A. 


IN. 


so- 


lo- 


CAYLLOMA 


SANTA 
LUCIA 


800 


MM. 


-1000 


--600 


=  -400 


-200 


— 1     oq    CO 


■.3.       lO       «£>      t^     00       0> 

CO      ■'J*       lO 


s  a 


OOO  r^  OOQOOOOiO 


s 


'^  "~*        s 


^ 


Fig.   103B. 

Fig.  102 — Monthly  rainfall  of  Santa  Lucia  for  the  j-ear  November,  1913, 
to  October,   1914.     No  rain  fell  in  July  and  August. 

Fig.  103A — Maximum,  mean  and  minimum  monthly  rainfall  of  Caylloma 
for  the  period  1896-7  to  1902-3.  July  was  absolutely  rainless.  Caylloma  is 
situated  immediately  east  of  the  crest  of  the  Maritime  Cordillera  in  a  position 
similar  to  that  of  Santa  Lucia   (see  Fig.  CG). 

Fie.  103B — Annual  rainfall  of  Caylloma  for  the  periods  1896-7  to  1902-3; 
1903-4  to  1910-11  and  for  1915-6  (incomplete:  May  and  Jvme,  months  of  low 
rainfall,  are  missing).  Means  for  the  respective  seven  and  eight  year  periods  are 
shown  and  the  rainfall  of  Santa  Lucia  for  the  single  observation  year  is  inserted 
for   comparison. 


166 


THE  ANDES  OF  SOUTHERN  PERU 


amount  of  precipitation  fluctuates  considerably  from  year  to  year. 
For  the  earlier  period,  with  a  mean  of  23.8  inches  the  minimum 
(1896-7)  was  8  inches  and  the  maximum  (1898-9)  36  inches.  For 
the  later  period,  1903-4  to  1910-11,  with  a  mean  of  29.5  inches  the 
minimum  (1904-5)  was  17.5  inches  and  the  maximum  (1906-7)  was 
43  inches. 


RAINFALL,   SANTA  LUCIA,   NOV.    1913     TO   OCT.    1914 


No  of 
fine  days 

No.  of 
rainy  days 

Atax.  for 
single  day 

Total  rainfall 
in  inches 

November   

9 

21 
15 
14 
17 
20 
13 
23 

3 

0  ' 

0 

7 
10 

1.150 
.700 
.010 
.910 
1.102 
0.31 
0.35 
0.05 
0.00 
0.00 
0.05 
0.14 

4.264  ^ 

December    

16 
17 

9 
11 
17 

8 
27 
31 

6.439 

January      

3.313 

February    

2.975 

Mareli    

4.381 

April    

0.92 

May   

1.63 

June       

0.07 

Julv    

0.00 

August    

September    

October   

31 
23 
21 

0.00 
0.35 
0.56 

Total 

24.902 

WIND 

An  analysis  of  the  wind  at  Santa  Lucia  sliows  an  excess  of 
north  and  south  winds  over  those  of  all  other  directions.  The 
wind-rose  for  the  entire  period  of  observation  (Fig.  104)  clearly 
expresses  this  fact.  When  tliis  element  is  removed  we  observe  a 
strongly  seasonal  distribution  of  the  wind.  The  winter  is  the  time 
of  north  and  south  winds.  In  summer  the  winds  are  chiefly  from 
the  northeast  or  the  southwest.  Among  single  months,  August 
and  February  show  this  fact  clearly  as  well  as  the  less  decisive 
character  of  the  summer  (February)  wind. 

The  mean  wind  velocity  for  the  month  of  February  was  540 
meters  per  minute  for  the  morning  and  470  meters  per  minute  for 
the  afternoon.    The  higher  morning  rate,  an  unusual  feature  of 


'  Tlie    record    is   copied    literally    without    regard    to    (Ik-    aliHiirdity   of    tlic    second 
nnd  third  decimal  places. 


METEOROLOGICAL  RECORDS 


167 


JUKE.  1913 


OCT. 


NOV. 


DEC. 


JAN.  1914 


FEB. 


MARCH 


APRIL 


MAY 


Fig.    104 — Monthly  wind   roses   for   Santa   Lucia,  June,   1913,  to   July,    1914,   and 
composite  rose  for  the  whole  period  of  observation. 


168 


THE  ANDES  OF  SOUTHERN  PERU 


the  weather  of  high  stations,  or  indeed  of  wind-phenomena  in  gen- 
eral, is  due,  however,  to  exceptional  changes  in  wind  strength  on 
two  days  of  the  month,  the  16th  and  25th,  when  the  velocity  de- 
creased from  a  little  less  than  a  thousand  meters  per  minute  in 
the  morning  to  4  and  152  meters  respectively  in  the  afternoon. 
More  typical  is  the  March  record  for  1914  at  Santa  Lucia,  when 
the  wind  was  always  stronger  in  the  afternoon  than  in  the  morn- 
ing, their  ratios  being  550  to  510. 


CLOUD 

The  greater  strength  of  the  afternoon  wind  would  lead  us  to 
uppose  that  the  cloudiness,  which  in  the  trade-wind  belt,  is  to  so 
great  an  extent  dependent  on  the  wind,  is  greatest  in  the  after- 
noon.   The  diagrams  bring  out  this  fact.    Rarely  is  the  sky  quite 
>clear  after  the  noon  hour.    Still  more  striking  is  the  contrast  be- 
tween the  morning  and  afternoon  if  we  combine  the  two  densest 
shadings  of  the  figures.    Light,  high-lying  cirrus  clouds  are  most 
characteristic  of  early  morning  hours.    They  produce  some  very 
striking  sky  effects  just  before  sunrise  as  they  catch  the  sun's  rays 
aloft.     An  hour  or  two  after  sunrise  they  disappear  and  small 
cumulus  clouds  begin  to  form.    These  grow  rapidly  as  the  winds 
begin  and  by  afternoon  become  bulky  and  numerous.    In  the  wet 
season  they  grow  into  the  nimbus  and  stratus  types  that  precede 
a  sudden  downpour  of  water  or  a  furious  hailstorm.    This  is  best 
seen  from  the  base  of  a  mountain  range  looking  towards  the  crest, 
where  the  cloud-  and  rain-making  processes  of  this  type  are  most 
active. 

CLOUD  ANALYSIS,  SANTA  LUCIA 


Type  of  cloud 


Nov. 
a.  m.    p.  m 


Dec.  Jan.  I'Vl) 

a.  m.  p.  m.'a.  m.  p.  m.  a.  in.   p.  m. 


Cirrus    6 

Cirro-stratus    — 

Cirro-cumulus   4 

Cumulus    I    •'{ 

Strato-cumuiiis    2 

Stratus    

Nimbus    

Clear    


15 

7 
4 


9 

11     3 

7    10 

10:      7 

1  — 


March 
a.  m.  p.  ni. 


0 
15 


14!    2 


13 
3 
1 


6  3 

17  10 

5  13 

—  3 

1  2 


Total 
a.  m.   p.  m. 


41      12 


37 

37 

14 

o 


38 

46 

36 

4 


METEOROLOGICAL  RECORDS 


169 


UNUSUAX,  WEATHER  PHENOMENA,  SANTA  LUCIA,  1913-14 

The  following  abstracts  are  selected  because  they  give  some 
important  features  of  the  weather  not  included  in  the  preceding 
tables  and  graphs.     Of  special  interest  are  the  strong  contrasts 


a..m. 


Jan. 


p.m. 


"<4£^222i^^ 


1  Clear 


0-2.5 


Scale  of  Cloudiness 
2.5-7.5 


7.5-10 


Completely 
Overcast 


Fig.   105 — Monthly  cloudiness  of  Santa  Lucia  from  January  to  July,   1914.     Mean 
cloudiness  for  the  whole  period  is  also  sho-\vn. 

between  the  comparatively  high  temperatures  of  midday  and  the 
sudden  ''tempests  "  accompanied  by  rain  or  hail  that  follow  the 
strong  convectional  movements  dependent  upon  rapid  and  unequal 
heating.  The  furious  winds  drive  the  particles  of  hail  like  shot. 
It  is  sometimes  impossible  to  face  them  and  the  pack  train  must 


170  THE  ANDES  OF  SOUTHERN  PERU 

be  halted  until  the  storm  has  passed.  Frequently  they  leave  the 
ground  white  with  hailstones.  We  encountered  one  after  another 
of  these  ''tempestades"  on  the  divide  between  Lambrama  and 
Antabamba  in  1911.  They  are  among  the  most  impetuous  little 
storms  I  have  ever  experienced.  The  longest  of  them  raged  on 
the  divide  from  two-o'clock  until  dark,  though  in  the  valleys  the 
sun  was  shining.  Fortunately,  in  this  latitude  they  do  not  turn 
into  heavy  snowstorms  as  in  the  Cordillera  of  northwestern 
Argentina,  where  the  passes  are  now  and  then  blocked  for' weeks  at 
a  time  and  loss  of  human  life  is  no  infrequent  occurrence,^  They 
do,  however,  drive  the  shepherds  down  from  the  highest  slopes  to 
the  mid-valley  pastures  and  make  travel  uncomfortable  if  not 
unsafe. 

ABSTRACT  FROM   DAILY   WEATHER   OBSERVATIONS,   SANTA  LUCIA,   1913-14 

NOVEMBER 

"  Tempest "  recorded  11  times,  distant  thunder  and  lightning  9  times. 
Unusual  weather  records:  "clear  sky,  scorching  sun,  good  weather"  (Nov.  29); 
"morning  sky  without  a  single  cloud,  weather  agreeable"   (Nov.  30). 

DECEMBER 

Clear  morning  sky  6  times.     Starry  night  or  part  of  night  7  times. 

Beginning  of  rain  and  strong  wind  frequently  observed  at  5-G  p.  M. 

"  Tempest "  mentioned  19  times — 5  times  at  midnight,  8  times  at  5-G  p.  M. 

JANUARY 

Clear  morning  sky  5  tiraas.     Starry  night  3  times. 

Rain,  actual  or  threatening,  characteristic  of  afternoons. 

"  Tempest,"  generally  about  5-6  p.  m.,  7  times. 

Sun  described  4  times  as  scorching  and,  when  without  wind,  heat  as  stifling. 

Weather  once  "  agreeable." 

FEBRUARY 

Constant  cloud  changes,  frequent  afternoon  or  evening  rains. 
"Tempest,"  genfrally  "1   i'-   m.  and  liilci-,  Ki.  limes. 

•  In  tlic  Enfltcrn  Cordillera,  however,  Hnowatorms  may  he  more  BeriouB.  Prior  to 
the  coriHtructlon  of  the  Unibaniha  Valley  Road  by  the  reruvian  government  tlie  three 
main  routes  to  the  Santa  Ana  portion  of  the  valley  proeeeded  via  the  passes  of  Salcantjiy, 
Pantiralla,  and  Yanaliuara  respectively.  Frequently  all  are  completely  Bnow-blocked 
and  fatalities  are  by  no  means  unknown.  In  1804  for  instiiiee  nine  persons  succumbed 
on  the  Yanaliuara  pass   (Raimondi,  op.  cit.,  p.  109). 


METEOROLOGICAL  RECORDS  171 

MARCH 

Twice  clear  morning  skies,  once  starry  night. 
Scorching  sun  and  stifling  heat  on  one  occasion. 

"  Tempest,"  generally  in  late  afternoon  and  accompanied  by  hail,  19  times. 
Observed  3  or  4  times  a  strong  "land  breeze"  (terral)  of  short  duration  (15-20 
mins.)  and  at  midnight. 

MOROCOCHA 

Morococha,  in  the  Department  of  Ancaclis,  Peru,  lies  in  76°  11' 
west  longitude  and  11°  45'  south  latitude  and  immediately  east  of 
the  crest  line  of  the  Maritime  Cordillera.  It  is  14,300  feet  above 
sea  level,  and  is  surrounded  by  mountains  that  extend  from  1,000 
to  3,000  feet  higher.  The  weather  records  are  of  special  interest 
in  comparison  with  those  of  Santa  Lucia.  Topographically  the 
situations  of  the  two  stations  are  closely  similar  hence  we  may 
look  for  climatic  differences  dependent  on  the  latitudinal  differ- 
ence. This  is  shown  in  the  heavier  rainfall  of  Morococha,  4° 
nearer  the  equatorial  climatic  zone.     (For  location  see  Fig.  66.) 

The  meteorological  data  for  1908-09  were  obtained  from  rec- 
ords kept  by  the  Morococha  Mining  Company  for  use  in  a  pro- 
jected hydro-electric  installation.  Other  data  covering  the  years 
1906-11  have  appeared  in  the  bulletins  of  the  Sociedad  Geogrd- 
fica  de  Lima.  These  are  not  complete  but  they  have  supplied  rain- 
fall data  for  the  years  1910-11;^"  those  for  1906  and  1907  have 
been  obtained  from  the  Boletvn  de  Minas.^^ 

Temperature  >> 

The  most  striking  facts  expressed  by  the  various  temperature 
curves  are  the  shortness  of  the  true  winter  season — its  restriction 
to  June  and  July — and  its  abrupt  beginning  and  end.  This  is  well  / 
known  to  anyone  who  has  lived  from  April  to  October  or  Novem- 
ber at  high  elevations  in  the  Central  Andes.  Winter  comes  on 
suddenly  and  with  surprising  regularity  from  year  to  year  dur- 
ing the  last  few  days  of  May  and  early  June.  In  the  last  week  of 
July  or  the  first  week  of  August  the  temperatures  make  an  equally 
sudden  rise.  During  1908  and  1909  the  mean  temperature  reached 
the  freezing  point  but  once  each  year — July  24  and  July  12  re- 

"Boletln  de  la  Sociedad  Geografica  de  Lima,  Vol.  27,  1911;  Vol.  28,  1912. 
^*  Boletin  del  Cuerpo  de  Ingenieros  de  Minas  del  Perfi,  No.  65,  1908. 


172  THE  ANDES  OF  SOUTHERN  PERU 

sjDectively.  The  absolute  iniiiimum  for  the  two  years  was  -  22°  C. 
July  of  1908  and  June  of  1909  are  also  the  months  of  smallest 
diurnal  variability,  showing  that  the  winter  temperatures  are 
maintained  with  great  reg-ularjty.  Like  all  tropical  high-level  sta- 
tions, Morococha  exhibits  winter  maxima  that  are  very  high  as 
compared  with  the  winter  maxima  of  the  temperate  zone.  In  both 
June  and  July  of  1908  and  1909  the  maximum  was  maintained  for 
about  a  week  above  55°  F.  (12.8'  C),  and  in  1909  above  60°  F. 
(15.6°  C),  the  mean  maximum  for  the  year  being  only  4.7°  F. 
higher.  For  equal  periods,  however,  the  maxima  fell  to  levels 
about  10°  F.  below  those  for  the  period  from  December  to 
May,  1908. 

It  is  noteworthy  that  the  lowest  maximum  for  1909  was  in 
October,  44°  F.  (6.7°  C);  and  that  other  low  maxima  but  little 
above  those  of  June  and  July  occur  in  almost  all  the  other  months 
of  the  year.  AVhile  1909  was  in  this  respect  an  exceptional  year, 
it  nevertheless  illustrates  a  fact  that  may  occur  in  any  month  of 
any  year.  Its  occurrence  is  generally  associated  with  cloudiness. 
One  of  the  best  examples  of  this  is  found  in  the  January  maximum 
curve  for  1909,  where  in  a  few  days  the  maxima  fell  12"  F.  Cloud 
records  are  absent,  hence  a  direct  comparison  cannot  bo  made,  but 
a  comparison  of  the  maximum  temperature  curve  with  the  graphic 
representation  of  mean  monthly  rainfall,  will  emphasize  this  rela- 
tion of  temperature  and  cloudiness.  February  was  the  wettest 
month  of  both  1908  and  1909.  In  sympathy  with  this  is  the  large 
and  sliarp  drop  from  the  January  level  of  tlio  maxima — the  highest 
for  the  year — to  the  February  level.  The  mean  temperatures  are 
affected  to  a  less  degree  because  the  cloudiness  retards  niglit  radia- 
tion of  heat,  thus  elevating  the  maxima.  Thus  in  1908  tlie  lowest 
minimum  for  both  January  and  February  was  28.4°  F.  ( — 2°  C). 
For  loril)  the  minima  for  January  and  February  were  27.5°  F. 
(—2.5"  C.)  .'iiid  2!).:r'  F.  (—1.5'  C.)  respectively. 

The  extent  to  wliicli  Iiil-Ii  niiniiiin  may  liohl  up  the  mean  tem- 
perature is  shown  liy  llic  fact  liiat  llie  mean  niontlily  tempera- 
ture for  January,  1908,  was  lower  tliaii  lor  i'^ebiiiary.  Single 
instances  illustrate  this  relation  equally  well.     For  example,  on 


CROC 


(/tOROC 


"A. 

M, 

I 

^ 

"~ 

FIG.  106  A  -  DIURNAL  TEMPERATURE,  MOR0(X>CHA.  1908 


ill 


IW^~^ 


^ 


^A 


ti 


^^fe:5;^ 


^^^^ 


*: 


-^ 


% 


:ei 


4<Q§£4^qli 


W2±5te 


ffftffmrhf^ 


FIG.  106  B  -  DIURNAL  TEMPERATURE.  MOROOOCHA,  1 


;p^5^; 


WS3 


^^ 


5^ 


t^KM^\^i 


m 


l£^-?2^x;?z:2 


=5i:2^s;S=^iBrEE^^^rt5g33^''-'' 


:n.^,V 


''M"-h.'r-; 


FIG.  106  D  -  DIDRNAL  RANGE  OF  TEMPERATURE.  HOROCOCHA.  1908 


sm 


Is 


i^ssii 


S^S; 


fS: 


'$& 


FIG.  106  E  -  DIURNAL  RANGE  OF 


MOROCOCHA.  1909 


iS 


ill 


1 


t-. 


v± 


m 


^W 


|||S|s 


S 


b 


^S 


5?i/£rf 


FIG.  106  G  -  DIURNAL  VARIABILITY  OF  TEMPERATURE,  MOROCOCHA,  1 


f^^feFFy^^TE 


\^^4/4^HJJ/''lvK4A/tvkiXyLvLA[ 


a^UaIaKLIA/wJ. 


FIG.  106  H  -  DIURNAL  VARIABILITY  OF  TEMPERATURE.  MOROCOCHA,  1909 


l€3FMdNA7yd34d^4j|\Abb^^ 


^1^  j:JzAH4^^|yA^l,=UkB  I 


X:3;j.'Zk7H  J  Jy\h 


FIG.  106  C  -  MEAN  MONTHLY  TEMPERATURE.  MOROCOCHA 


FIG. 

06  F- 

MONTHLY  MEANS  OF  DIURNAL  RANGE 

)F  TEMPERATURE.  MOROCOCHA 

p  n 

^, 

SI 

J.IJ, 

A, 

^ 

^• 

^ 

.>     ,M_U^ 

^ 

" 

^ 

" 

' 

■" 

1  !L 

_;' 

■ 

" 

^ 

«! 

lis' 

_L 

yi  ii4» 

li 

rf 

^ 

=^ 

_ 

_ 

_ 

-^^ 

^  1  1 

Lj 

„ 

.— 

_j 

• 

_ 

_j 

^ 

[=d 

iMsTism 

Ld 

Lj 

J 

Lj 

wU 

METEOROLOGICAL  RECORDS 


173 


March  5tli,  1908,  there  occurred  the  heaviest  rainfall  of  that  year. 
The  maximum  and  minimum  curves  almost  touch.  The  middle  of 
April  and  late  September,  1909,  are  other  illustrations.  The  rela- 
tionship is  so  striking  that  I  have  put  the  two  curves  side  by  side 
and  have  had  them  drawn  to  the  same  scale. 

FKEQUENCY  OF  THE  DIURNiVL.  VARIABILITY,  MOROCOCHA,  1908  AND  1909 

1908 


Degrees  F. 

J. 

F. 

M. 

A. 

M. 

J. 

J. 

A. 

s. 

0. 

N. 

D. 

Total  No. 
of  days 

0 



3 

2 

3 





2 

1 

3 

1 

1 

3 

19 

0-1 

6 

5 

6 

10 

9 

10 

13 

10 

8 

6 

c 

5 

94 

1-2 

4 

1 

3 

7 

5 

3 

7 

7 

8 

6 

6 

4 

61 

2-3 

6 

1 

3 

4 

9 

2 

2 

4 

4 

7 

7 

4 

53 

3-4 

5 

3 

2 

3 

3 

4 

2 

9 

4 

5 

3 

5 

48 

4-5 

2 

3 

1 

1 

2 

5 

5 

— 

1 

1 

6 

3 

30 

Over  5 

3 

4 

3 

2 

3 

6 

— 

— 

2 

5 

1 

5 

34 

Days  per 

26 

20 

20 

30 

31 

30 

31 

31 

30 

31 

30 

29 

339 

month 

1909 


Degrees  F. 

J. 

F. 

M. 

A. 

M. 

J. 

J. 

A. 

s. 

o. 

N. 

D. 

Total 
No.  of 
days 

Mean 

for  1908 

-1909 

0 

6 

1 

4 

2 

1 

2 

4 

4 

3 

6 

2 

1 

36 

27.5 

0-1 

9 

8 

5 

6 

6 

7 

8 

13 

9 

4 

11 

10 

96 

95 

1-2 

4 

6 

8 

3 

11 

14 

3 

3 

5 

3 

9 

6 

75 

68 

2-3 

3 

7 

4 

8 

4 

3 

6 

6 

4 

6 

1 

3 

55 

54 

3-4 

4 

5 

3 

6 

4 

4 

4 

3 

6 

3 

2 

5 

49 

48.5 

4-5 

1 

1 

5 

1 

2 

— 

2 

1 

1 

2 

— 

2 

18 

24 

Over  5 

4 

— 

2 

4 

3 

— 

4 

1 

2 

7 

5 

3 

35 

34.5 

Days  per 

31 

28 

31 

30 

31 

30 

31 

31 

30 

31 

30 

30 

364 

351.5 

month 

RAINFALL 

The  annual  rainfall  of  Morococha  is  as  follows : 

1900 28  inches (    712  mm.) 

1907 40       "     (1,011mm.) 

''  1908 57       "     (1,450  mm.) 

1909 45       "     (1,156  mm.) 

1910 47       "     (1,195  mm.) 

1911 25       "     (    622  mm.) 

*^  This   figure    is   approximate:    some   days'    records   were  missing   from   the   first 
three  months  of  the  year  and  the  total  was  estimated  on  a  proportional  basis. 


174 


THE  ANDES  OF  SOUTHERN  PERU 


a 
o 


00 

O 


s 

'T' 

1  s 

I 

—i — ? 

Nvaw 

II6I 

^ 

0I6I 
6061 
S06I 
i06I 
9061 

■■  1 

m 


Si   * 


IS     ?r 


PQ 


2   ei. 


o       ^ 


■  a 


CO    ei 


S^,  ^ 


e    9 

5  '=3 
S   ^ 


>>  a 

.5   c 


-^    a> 


G  t^ 

^  e« 

O  ^ 

-C  --I 

X  I— I 

<5  -^ 

tb  a 


^5 

8  |o 
2  § 


^ 


<. 


d  a 
•«  2 
rt  "*^ 

2  '5 

o'    l>« 

(^  rd 

c 
o 

a 


METEOROLOGICAL  RECORDS  175 

The  mean  for  the  above  six  years  amounts  to  40  inches  (1,024 
mm.).  This  is  a  value  considerably  higher  than  that  for  Cayl- 
loma  or  Santa  Lucia.  The  greater  rainfall  of  Morococha  is  prob- 
ably due  in  part  to  its  more  northerly  situation.  An  abnormal 
feature  of  the  rainfall  of  1908,  the  rainiest  year,  is  the  large 
amount  that  fell  in  June.  Ordinarily  June  and  July,  the  coldest 
months,  are  nearly  or  quite  rainless.  The  normal  concurrence 
of  highest  temperatures  and  greatest  precipitation  is  of  course 
highly  favorable  to  the  plant  life  of  these  great  altitudes.  Full 
advantage  can  be  taken  of  the  low  summer  temperatures  if  the 
growing  temperatures  are  concentrated  arid  are  accompanied  by 
abundant  rains.  Since  low  temperatures  mean  physiologic  dry- 
ness, whether  or  not  rains  are  abundant,  the  dryness  of  the  winter/ 
months  has  little  effect  in  restricting  the  range  of  Alpine  species. 

The  seasonal  distribution  of  rain  helps  the  plateau  people  as 
well  as  the  plateau  plants.  The  transportation  methods  are 
primitive  and  the  trails  mere  tracks  that  follow  the  natural  lines 
of  topography  and  drainage.  Coca  is  widely  distributed,  likewise 
corn  and  barley  which  grow  at  higher  elevations,  and  wool  must 
be  carried  down  to  the  markets  from  high-level  pastures.  In  the 
season  of  rains  the  trails  are  excessively  wet  and  slippery,  the 
streams  are  often  in  flood  and  the  rains  frequent  and  prolonged. 
On  the  other  hand  the  insignificant  showers  of  the  dry  or  non- 
growing  season  permit  the  various  products  to  be  exchanged 
over  dry  trails.  / 

The  activities  of  the  plateau  people  have  had  a  seasonal  expres- 
sion from  early  times.  Inca  chronology  counted  the  beginning  of 
the  year  from  the  middle  of  May,  that  is  when  the  dry  season  was 
well  started  and  it  was  inaugurated  with  the  festivals  of  the  Sun. 
With  the  exception  of  June  when  the  people  were  entirely  busied 
in  the  irrigation  of  their  fields,  each  month  had  its  appropriate 
feasts  until  January,  during  which  month  and  February  and 
March  no  feasts  were  held.  April,  the  harvest  month,  marked  the 
recommencement  of  ceremonial  observances  and  a  revival  of  social 
life.^^ ' 

"  Christoval  de  Molina,  The  Fables  and  Rites  of  the  Yncas,  Hakluyt  See.  Pubis.,  1st 
Ser.,  No.  48,  1873. 


176  THE  ANDES  OF  SOUTHERN  PERU 

In  Spanish  times  the  ritualistic  festivals,  incorporated  with 
fairs,  followed  the  seasonal  movement.  Today  progress  in  trans- 
portation has  caused  the  decadence  of  many  of  the  fairs  but  others 
still  survive.  Thus  two  of  the  most  famous  fairs  of  the  last  cen- 
tury, those  of  Vilque  (province  of  Puno)  and  Yunguyo  (province 
of  Chucuito),  were  held  at  the  end  of  May  and  the  middle  of 
August  respectively.  Copacavana,  the  famous  shrine  on  the 
shores  of  Titicaca,  still  has  a  well-attended  August  fair  and 
Huari,  in  the  heart  of  the  Bolivian  plateau,  has  an  Easter  fair 
celebrated  throu2:hout  the  Andes. 


'o^ 


COCHABAMBA 

Cochabamba,  Bolivia,  lies  8,000  feet  above  sea  level  in  a  broad 
basin  in  the  Eastern  Andes.  The  Cerro  de  Tunari,  on  the  north- 
west, has  a  snow  and  ice  cover  for  part  of  the  year.  The  tropical 
forests  lie  only  a  single  long  day's  journey  to  the  northeast.  Yet 
the  basin  is  dry  on  account  of  an  eastern  front  range  that  keeps 
out  the  rain-bearing  trade  winds.  The  Rio  Grande  has  here  cut 
a  deep  valley  by  a  roundabout  course  from  the  mountains  to  the 
plains  so  that  access  to  the  region  is  over  bordering  elevations. 
The  basin  is  chiefly  of  structural  origin. 

The  weather  records  from  Cochabamba  are  very  important.  I 
could  obtain  none  but  temperature  data  and  tliej'-  are  complete  for 
190G  only.  Data  for  1882-85  were  secured  by  von  Boeck  '*  and  they 
have  been  quoted  by  Sievers  and  liann.  The  mean  annual  tem- 
perature for  1906  was  G1.9°  F.  (16.6°  C),  a  figure  in  close  agree- 
ment with  von  Boeck's  mean  of  60.8°  F.  (16°  C).  Tlie  moiilhly 
means  indicate  a  level  of  temperature  favorable  to  agriculhiro. 
The  basin  is  in  fact  the  most  fertile  and  liiglily  cultivated  area  of 
its  kind  in  Bolivia.  Bananas,  as  well  as  many  other  tropical  and 
subtroi)ic;il  plants,  grow  in  the  central  plaza.  Tlie  niglits  of  mid- 
winter are  uncomfortably  cool;  ;m(l  llic  davs  of  nrKlsuiiiiiior  are 


'♦Sec  MotcorologisdiP  Zcitsolirift,  \'<.l.  n.  p.  Iflf),  IHSH.  Also  citr.l  hy  .1.  Il:iini  in 
Hnn<llinfli  clrr  f'liriititolo^ic,  Vol.  2,  St  ntl^'art,  1S!»7  ;  W.  SirvcrH,  Siiil  iind  Mil  IchiiiicrikM, 
Leipzig  and  Vienna,  1914,  p.  334. 


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FIG.  108  G  -DIURNAL  VARIABILITY,  COCHABAMBA,  1906 


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FIG.  108  C  -  MEAN  MONTHLY  TEMPERATURES,  COCHABAMBA 


.  108  F  -  MONTHLY  MEANS  OF  DIURNAL  RANGE.  COCHABAMBA 


FIG.  108  H  -  PrURKAL  VARIABILITY,  COCHABAMBA.  1907 


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METEOROLOGICAL  RECORDS 


177 


uncomfortably  hot  but  otherwise  the  temperatures  are  delightful. 
The  absolute  extremes  for  1906  were  81.5°  F.  (27.5°  C.)  on  Decem- 
ber 11,  and  39.9°  F.  (4.4°  C.)  on  July  15  and  16.  The  (uncor- 
rected) readings  of  von  Boeck  give  a  greater  range.  High  minima 
rather  than  high  maxima  characterize  the  summer.  The  curve  for 
1906  shows  the  maxima  for  June  and  July  cut  off  strikingly  by  an 
abrupt  drop  of  the  temperature  and  indicates  a  rather  close  re- 
striction of  the  depth  of  the  season  to  these  two  months,  which  are 
also  those  of  greatest  diurnal  range. 

The  rainfall  of  about  18  inches  is  concentrated  in  the  summer 
season,  85  per  cent  falling  between  November  and  March.  Dur- 
ing this  time  the  town  is  somewhat  isolated  by  swollen  streams 
and  washed  out  trails :  hence  here,  as  on  the  plateau,  there  is  a  dis- 
tinct seasonal  distribution  of  the  work  of  planting,  harvesting, 
moving  goods,  and  even  mining,  and  of  the  general  commerce  of 
the  towns.  There  is  an  approach  to  our  winter  season  in  this  re- 
spect and  in  respect  of  a  respite  from  the  almost  continuously 
high  temperatures  of  summer.  The  daytime  temperatures  of  sum- 
mer are  however  mitigated  by  the  drainage  of  cool  air  from  the 
surrounding  highlands.  This,  indeed,  prolongs  the  period  re- 
quired for  the  maturing  of  plants,  but  there  are  no  harmful  results 
because  freezing  temperatures  are  not  reached,  even  in  winter. 


MONTHLY  TEMPERATURES,  COCHABAMBA,  1906 


Month 


January    . 
February 
March    . . . 
April    . . . . 

May   

June   .... 

July    

August   . . 
September 
October    . . 
November 
December 


Mean  Min. 


55.7 
61.2 

59.8 

55.06 

50.9 

47.1 

44.8 

49.9 

55.6 

56.1 

58.1 

58.6 


Mean  Max. 


72.25 
71.3 

72.6 
70.8 
68.7 
65.6 
64.9 
68.0 
73.2 
73.4 
75.7 
73.9 


Mean  Range 


16.65 
10.1 

12.8 

15.74 

17.8 

18.5 

20.1 

18.1 

17.6 

17.3 

17.6 

15.3 


Daily  Mean 


63.3 
65.5 
65.5 
62.2 
59.1 
55.6 
54.1 
58.2 
63.7 
64.0 
66.2 
65.8 


178 


THE  ANDES  OF  SOUTHERN  PERU 


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Fig.  114 — Typical  afternoon  cloud  composition  at  Santa  Ana  during  the  dry  season. 

Fig.  115 — Temperature  curve  for  Abancay  drawn  from  data  obtained  by  hourly 
readings  on  September  27,  1911.  Dry  bulb  readings  are  shown  by  a  heavy  solid 
line,  wet  bulb  readings  by  a  dotted  line.  The  heavy  broken  line  shows  the  normal 
curve  when  the  sky  is  unobscured  by  cloud.  The  reduction  in  temperature  with  cloud 
is  very  marked. 


METEOROLOGICAL  RECORDS  179 

FREQUENCY  OF  DIURNAL  VARIABILITY  AT   COCHABAMBA,   1906 


Degrees  F. 

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A  series  of  curves  shows  the  daily  march  of  temperature  at 
various  locations  along  the  seventy-third  meridian.  Figs.  109  to 
113  are  for  the  Urubamba  Valley.  Respectively  they  relate  to 
Pongo  de  Mainique,  1,200  feet  elevation  (365  m.),  the  gateway  to 
the  eastern  plains;  Yavero,  1,600  feet  (488  m.),  where  the  tribu- 
tary of  this  name  enters  the  main  stream ;  Santo  Anato  1,900  feet 
(580  m.) ;  Sahuayaco,  2,400  feet  (731  m.),  and  Santa  Ana,  3,400 
feet  (1,036  m.),  one  of  the  outposts  of  civilization  beyond  the  East- 
ern Cordillera.  The  meteorological  conditions  shown  are  all  on 
the  same  order.  They  are  typical  of  dry  season  w^eather  on  the 
dry  floor  of  a  montana  valley.  The  smooth  curves  of  clear  days 
are  marked  by  high  mid-day  temperatures  and  great  diurnal 
range.  Santo  Anato  is  a  particularly  good  illustration :  the  range 
for  the  24  hours  is  38°  F.  (21.1°  C).  This  site,  too,  is  remarkable 
as  one  of  the  most  unhealthful  of  the  entire  valley.  The  walls  of 
the  valley  here  make  a  sharp  turn  and  free  ventilation  of  the 
valley  is  obstructed.  During  the  wet  season  tertian  fever  pre- 
vails to  a  degree  little  known  east  of  the  Cordillera,  though 
notorious  enough  in  the  deep  valleys  of  the  plateau.  The  curves 
show  relative  humidity  falling  to  a  very  low  minimum  on  clear 
days.  At  Santo  Anato  and  Santa  Ana,  for  example,  it  drops 
below  30  per  cent  during  the  heat  of  the  day.  Afternoon  cloudi- 
ness, however,  is  a  common  feature  even  of  the  dry  season. 
A  typical  afternoon  cloud  formation  is  shoT\Ti  in  Fig.  114.  The 
effect  on  temperature  is  most  marked.  It  is  well  shown  in  the 
curve  for  August  20  and  22  at  Yavero.    Cloudiness  and  precipita- 


180 


THE  ANDES  OF  SOUTHERN  PERU 


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Fia.  118. 


Figs.  110118 — Ti'nipcratiirc  ciiivcs  for  lociitioiis  in  tlic  Maiitimc  CordilUTu  aiul 
Its  westfrn  vallf-ys,  Octolicr,  1911.  I'm-  cimslruction  of  curvcB  see  Fig^. 
109-11.3.  Fig.  110  is  for  Camp  1.3  on  (lie  liorllicrn  slopi'  of  llio  Maritime  Cordillera 
(whicli  liero  runs  from  oast  to  west),  OcIoImt  l.'Mf);  Fig,  117  for  Colalmnsi,  October 
2(5;  Fig.  118  for  Salamanca,  October  .31. 

tion  increase  during  tho  summer  months.  At  Santa  Ana  the 
rainfall  for  the  year  ]894-95  amounted  to  50  inches,  of  which  GO 
per  cent  fell  between  December  and  March.    For  a  discussion  of 


METEOROLOGICAL  RECORDS 


181 


topographic  features  that  have  some  highly  interesting  climatic 
effects  in  the  eastern  valleys  of  Peru  see  Chapter  VL 

Abancay,  8,000  feet  (2,440  m.),  in  one  of  the  inter- Andean 
basins,  is  situated  in  the  zone  of  marked  seasonal  precipitation. 


Noon         6  p.m.        Midi 

Fig.   119. 


6  a.m 


6  a.m.      Noon       6  p.m.        Midt. 
Fig.   120. 


Ca.m. 


Figs.  119-120 — Temperature  curves  for  the  Coast  Desert,  November,  1911.  Fig. 
119  is  for  Aplao,  November  4  and  5;  and  Fig.  120  for  CamanS,  November  9  and  10. 
For  construction  of  curves  see  Figs.  109  to  113. 

The  single  day's  record  shows  the  characteristic  effect  of  cloud 
reducing  the  maximum  temperature  of  the  day  and  maintaining 
the  relative  humidity. 

Camp  13, 15,400  feet  (4,720  m.),  lies  near  the  crest  of  the  Mari- 
time Cordillera  a  little  south  of  Antabamba.  Afternoon  storms 
are  one  of  its  most  significant  features.  Cotahuasi,  9,100  feet 
(2,775  m.)  is  near  the  head  of  a  west-coast  valley.  Its  low  humid- 
ity is  worthy  of  note.  That  for  Salamanca,  12,700  feet  (3,870  m.), 
is  similar  but  not  so  marked. 

Aplao,  3,100  feet  (945  m.),  and  Camana  at  the  seacoast  are 
stations  in  the  west-coast  desert.  The  interior  location  of  the 
former  gives  it  a  greater  range  of  temperature  than  Camana,  yet 
even  here  the  range  is  small  in  comparison  with  the  diurnal  ex- 
tremes of  the  montana,  and  the  tempering  effect  of  the  sea-breeze 
is  clearly  apparent.  Camana  shows  a  diurnal  temperature  range 
of  under  10°  F.  and  also  the  high  relative  humidity,  over  70  per 
cent,  characteristic  of  the  coast. 


PART  II 
PHYSIOGRAPHY  OF  THE  PERUVIAN  ANDES 

CHAPTER  XI 
THE  PERUVIAN  LANDSCAPE 

Fkom  the  west  coast  the  great  Andean  Cordillera  appears  to 
have  little  of  the  regularity  suggested  by  our  relief  maps.  Steep 
and  high  cliffs  in  many  places  form  the  border  of  the  land  and 
obstruct  the  view;  beyond  them  appear  distant  summits  rising  into 
the  zone  of  clouds.  Where  the  cliffs  are  absent  or  low,  one  may 
look  across  a  sun-baked,  yellow  landscape,  generally  broken  by  ir- 
regular foothills  that  in  turn  merge  into  the  massive  outer  spurs 
and  ranges  of  the  mountain  zone.  The  plain  is  interrupted  by 
widely  separated  valleys  whose  green  lowland  meadows  form  a 
brilliant  contrast  to  the  monotonous  browns  and  yellows  of  the 
shimmering  desert.  In  rare  situations  the  valley  trenches  enable 
one  to  look  far  into  the  Cordillera  and  to  catch  memorable 
glimpses  of  lofty  peaks  capped  with  snow. 

If  the  traveler  come  to  the  west-coast  landscape  from  the  well- 
molded  English  hills  or  the  subdued  mountains  of  Vermont  and 
New  Hampshire  with  their  artistic  blending  of  moderate  profiles, 
he  will  at  first  see  nothing  but  disorder.  The  scenery  will  be  im- 
pressive and,  in  places,  extraordinary,  but  it  is  apparently  com- 
posed of  elements  of  the  greatest  diversity.  All  the  conceivable 
variations  of  form  and  color  are  expressed,  with  a  predominance 
of  bold  rugged  aspects  that  give  a  majestic  appearance  to  the 
mountain-bordered  shore.  One  looks  in  vain  for  some  sign  of  a 
quiet  view,  for  some  uniformity  of  features,  for  some  landscape 
that  will  remind  him  of  the  familiar  hills  of  home.  The  Andes\ 
are  aggressive  mountains  that  front  the  sea  in  formidable  spurs 
or  desert  ranges.    Could  we  see  in  one  view  their  entire  elevation  \/ 

183 


184  THE  ANDES  OF  SOUTHERN  PERU 

from  depths  of  over  20,000  feet  beneath  sea  level  to  snowy  sum- 
mits, a  total  altitude  of  40,000  feet  (12,200  m.),  their  excessive 
boldness  would  be  more  apparent.  No  other  mountains  in  the 
^ world  are  at  once  so  continuously  lofty  and  so  near  a  coast  which 
drops  off  to  abyssal  depths. 

The  view  from  the  shore  is,  however,  but  one  of  many  which 
the  Andes  exhibit.  Seen  from  the  base  the  towering  ranges  dis- 
play a  stern  aspect,  but,  like  all  mountains,  their  highest  slopes 
and  spurs  must  be  crossed  and  re-crossed  before  the  student  is 
aware  of  other  aspects  of  a  quite  different  nature.  The  Andes 
must  be  observed  from  at  least  three  situations :  from  the  floors 
of  the  deep  intermontane  valleys,  from  the  intermediate  slopes 
and  summits,  and  from  the  uppermost  levels  as  along  the  range 
crests  and  the  highest  passes.  Strangely  enough  it  is  in  the  sum- 
mit views  that  one  sees  the  softest  forms.  At  elevations  of  14,000 
to  16,000  feet  (4,270  to  4,880  m.),  where  one  would  expect  rugged 
spurs,  serrate  chains,  and  sharp  needles  and  horns,  one  comes  fre- 
quently upon  slopes  as  well  graded  as  those  of  a  city  park — grass- 
covered,  waste-cloaked,  and  with  gentle  declivity  (Figs.  121-124). 

The  graded,  waste-cloaked  slopes  of  the  higher  levels  are  in- 
terpreted as  the  result  of  prolonged  denudation  in  an  erosion 
cycle  which  persisted  through  the  greater  part  of  the  Tertiary 
period,  and  which  was  closed  by  uplifts  aggregating  at  least  sev- 
eral thousands  of  feet.  Above  the  level  of  the  mature  slopes  rise 
the  ragged  profiles  and  steep,  naked  declivities  of  the  snow-capped 
mountains  wliich  bear  residual  relations  to  Ww  softer  forms  at 
their  bases.  They  are  formed  upon  rock  masses  of  greater 
original  elevation  and  of  higher  resistance  to  denudation.  Though 
they  are  dominating  toi)ograpliic  features,  they  are  nuich  less  ex- 
tensive and  significant  than  the  tame  landscape  which  they  sur- 
mount. 

Below  the  level  of  the  mature  slopes  are  topographic  features 
of  equal  prominence:  gorges  and  canyons  uj)  to  7,000  feet  deep. 
The  deeply  intrenched  streams  are  broken  by  waterfalls  and  al- 
most continuous  rapids,  the  valley  walls  ai'c  so  abru])t  that  one 
may,  in  places,  roll  stones  down  a  4,()00-foot  incline  to  the  river 


Fig.  121. 


:r-  f^v^M>i>iifi''!>S'^'!y^'t''9SpByTtt-^ 


Fig.    1-Jii. 

Fig.  121 — Looking  north  from  tlie  hill  near  Ante  in  the  Anta  basin  north  of 
Cuzco.  Typical  composition  of  slopes  and  intermont  basins  in  the  Central  Andes. 
Alluvial  fill  in  the  foreground;  mature  slopes  in  the  background;  in  the  extreme  back- 
ground the  snow-capped  crests  of  the  Cordillera  Vilcapampa. 

Fig.  122 — Showing  topographic  conditions  before  the  formation  of  the  deep  canyons 
in  the  Maritime  Cordillera.  The  view,  looking  across  a  tributary  canyon  of  the 
Antabamba  river,  shows  in  the  background  the  main  canyon  above  Huadquirca.  Com- 
pare with  Fig.  60. 


THE  PERUVIAN  LANDSCAPE 


185 


bed,  and  the  tortuous  trail  now  follows  a  stream  in  the  depths  of 
a  profound  abyss,  now  scales  the  walls  of  a  labyrinthine  canyon. 

The  most  striking  elements  of  scenery  are  not  commonly  the 
most  important  in  physiography.  The  oldest  and  most  significant 
surface  may  be  at  the  top  of  the  country,  where  it  is  not  seen  by 
the  traveler  or  where  it 
cannot  impress  him,  ex- 
cept in  contrast  to  fea- 
tures of  greater  height 
or  color.  The  layman 
frequently  seizes  on  a 
piece  of  bad-land  erosion 
or  an  outcrop  of  bright- 
colored  sandstone  or  a 
cliff  of  variegated  clays  or 
a  snow-covered  mountain  as  of  most  interest.  All  we  can  see 
of  a  beautiful  snow-clad  peak  is  mere  entertaimnent  compared 
with  what  subdued  waste-cloaked  hill-slopes  may  show.  We  do 
not  wish  to  imply  that  everywhere  the  tops  of  the  Andes  are 
meadows,  that  there  are  no  great  scenic  features  in  the  Peruvian 
mountains,  or  that  they  are  not  worth  while.  But  we  do  wish  to 
say  that  the  bold  features  are  far  less  important  in  the  interpre- 
tation of  the  landscape. 

Amid  all  the  variable  forms  of  the  Peruvian  Cordillera  certain 
strongly  developed  types  recur  persistently.  That  their  impor- 
tance and  relation  may  be  appreciated  we  shall  at  once  name  them 
categorically  and  represent  them  in  the  form  of  a  block  diagram 
(Fig.  126).    The  principal  topographic  types  are  as  follows: 


Fig.   125 — Mature  upper  and  young  lower 
slopes  at  the  outlet  of  the  Cuzco  basin. 


1.  An  extensive  system  of  high-level,  well-graded,  mature  slopes,  below  which 
are: 

2.  Deep  canyons  with  steep,  and  in  places,  eliffed  sides  and  narrow  floors,  and 
above  which  are : 

3.  Lofty  residual  mountains  composed  of  resistant,  highly  deformed  rock,  now 
sculptured  into  a  maze  of  serrate  ridges  and  sharp  commanding  peaks. 

4.  Among  the  forms  of  high  importance,  yet  causally  unrelated  to  the  other 
closely  associated  types,  are  the  volcanic  cones  and  plateaus  of  the  western  Cordil- 
lera. 


186 


THE  ANDES  OF  SOUTHERN  PERU 


5.  At  the  valley  heads  are  a  full  complement  of  glacial  features,  such  as  cirques, 
hanging  valleys,  reversed  slopes,  terminal  moraines,  and  valley  trains. 

6.  Finally  there  is  in  all  the  valley  bottoms  a  deep  alluvial  fill  formed  during 
the  glacial  period  and  now  in  process  of  dissection. 

Though  there  are  in  many  places  special  features  either  re- 
motely related  or  quite  unrelated  to  the  principal  enumerated 
types,  they  belong  to  the  class  of  minor  forms  to  which  relatively 
small  attention  will  be  paid,  since  they  are  in  general  of  small  ex- 
tent and  of  purely  local  interest. 

The  block  diagram  represents  all  of  these  features,  though  of 


Fig.    126 — Block   diagram   of   tlie   typical   physiographic   features   of   the   rcruvian 
Andes. 

necessity  somewhat  more  closely  associated  than  they  occur  in 
nature.  Reference  to  the  photographs,  Figs.  121-124,  will  make  it 
clear  that  the  diagram  is  somewhat  ideal :  on  the  other  hand  the 
photographs  together  include  all  tlic  features  which  the  diagram 
displays.  In  descending  from  any  of  the  higher  passes  to  the  val- 
ley floor  one  passes  in  succession  down  a  steep,  well-like  cirque  at 
a  glaciated  valley  head,  across  a  rocky  terminal  moraine,  then 
down  a  stair-like  trail  cut  into  the  steep  scarps  which  everywhere 
mark  the  descent  to  tlie  main  valley  floors,  over  one  after  another 
of  the  confluent  alluvial  fans  that  together  constitute  a  large  part 
of  the  valley  fill,  and  finally  down  the  steep  sides  of  the  inner  val- 
ley to  the  boulder-strewn  bed  of  the  ungraded  river. 


THE  PERUVIAN  LANDSCAPE  187 

We  shall  now  turn  to  each  group  of  features  for  description 
and  explanation,  selecting  for  first  consideration  the  forms  of 
widest  development  and  greatest  significance — the  high-level  ma- 
ture slopes  lying  between  the  lofty  mountains  which  rise  above 
them  and  the  deep,  steep-walled  valleys  sunk  far  below  them. 
These  are  the  great  pasture  lands  of  the  Cordillera;  their  higher 
portions  constitute  the  typical  puna  of  the  Indian  shepherds.  In' 
many  sections  it  is  possible  to  pasture  the  vagrant  flocks  almost 
anywhere  upon  the  graded  slopes,  confident  that  the  ichu,  a 
tufted  forage  grass,  will  not  fail  and  that  scattered  brooks  and 
springs  will  supply  the  necessary  water.  At  nightfall  the  flocks 
are  driven  do^vn  between  the  sheltering  walls  of  a  canyon  or  in 
the  lee  of  a  cliff  near  the  base  of  a  mountain,  or,  failing  to  reach 
either  of  these  camps,  the  shepherd  confines  his  charge  within  the 
stone  walls  of  an  isolated  corral. 

In  those  places  where  the  graded  soil-covered  slopes  lie  within 
the  zone  of  agriculture — below  14,000  feet — they  are  cultivated, 
and  if  the  soil  be  deep  and  fertile  they  are  very  intensively  culti- 
vated. Between  Anta  and  Urubamba,  a  day's  march  north  of 
Cuzco,  the  hill  slopes  are  covered  with  wheat  and  barley  fields 
which  extend  right  up  to  the  summits  (Fig.  134),  In  contrast  are 
the  uncultivated  soil-less  slopes  of  the  mountains  and  the  bare  val- 
ley walls  of  the  deeply  intrenched  streams.  The  distribution  of 
the  fields  thus  brings  out  strongly  the  principal  topographic  rela- 
tions. Where  the  softer  slopes  are  at  too  high  a  level,  the  climatic 
conditions  are  extreme  and  man  is  confined  to  the  valley  floors 
and  lower  slopes  where  a  laborious  system  of  terracing  is  the  first 
requirement  of  agriculture. 

The  appearance  of  the  country  after  the  mature  slopes  had 
been  formed  is  brought  out  in  Fig.  122.  The  camera  is  placed  on 
the  floor  of  a  still  undissected,  mature  valley  which  shows  in  the 
foreground  of  the  photograph.  In  the  middle  distance  is  a  valley 
whose  great  depth  and  steepness  are  purposely  hidden;  beyond 
the  valley  are  the  smoothly  graded,  catenary  curves,  and  inter- 
locking spurs  of  the  mature  upland.  In  imagination  one  sees  the 
valleys  filled  and  the  valley  slopes  confluent  on  the  former  (now 


188  THE  ANDES  OF  SOUTHERN  PERU 

imaginary)  valley  floor  which  extends  without  important  change 
of  expression  to  the  border  of  the  Cordillera.  No  extensive  cliffs 
occur  on  the  restored  surface,  and  none  now  occur  on  large  tracts 
of  the  still  undissected  upland.  Since  the  mature  slopes  represent 
a  long  period  of  weathering  and  erosion,  their  surfaces  were  cov- 
ered with  a  deep  layer  of  soil.  Where  glaciation  at  the  higher 
levels  and  vigorous  erosion  along  the  canyons  have  taken  place, 
the  former  soil  cover  has  been  removed;  elsewhere  it  is  an  impor- 
tant feature.  Its  presence  lends  a  marked  softness  and  beauty  to 
these  lofty  though  subdued  landscapes. 

The  graded  mountain  slopes  were  not  all  developed  (1)  at  the 
same  elevation,  nor  (2)  upon  rock  of  the  same  resistance  to  de- 
nudation, nor  (3)  at  the  same  distance  from  the  major  streams, 
nor  (4)  upon  rock  of  the  same  structure.  It  follows  that  they  will 
not  all  display  precisely  the  same  form.  Upon  the  softer  rocks  at 
the  lowest  levels  near  the  largest  streams  the  surface  was  Avorn 
down  to  extremely  moderate  slopes  with  a  local  relief  of  not  more 
than  several  hundred  feet.  Conversely,  there  are  quite  unreduced 
portions  whose  irregularities  have  mountainous  proportions,  and 
between  these  extremes  are  almost  all  possible  variations.  Though 
the  term  mature  in  a  broad  way  expresses  the  stage  of  develop- 
ment which  the  land  had  reached,  post  mature  should  be  applied 
to  those  portions  wliich  suffered  the  maximum  reduction  and  now 
exhibit  the  softest  profiles.  At  no  place  along  the  73rd  meridian 
was  denudation  carried  to  the  point  of  even  local  peneplanation. 
All  of  the  major  and  some  of  the  minor  divides  bear  residual  ele- 
vations and  even  a])i)roximately  plane  surfaces  do  not  exist. 

Among  the  most  important  features  of  the  mature  slopes  are 
(1)  their  great  areal  extent — they  are  exhibited  tlirougliout  the 
wliole  Central  Andes,  (2)  their  persistent  development  upon  rocks 
of  whatever  structure  or  degree  of  hardness,  and  (3)  their  pres- 
ent great  elevation  in  s|)ii('  of  moderate  grades  iiidic'iiivc  of  llieir 
dcveloj)niciii  ;it  n  much  lowci-  aKilndc  Mature  slopes  of  equiva- 
lent form  are  developed  in  widely  separated  localities  in  the  Cen- 
tral Andes:  in  every  valley  about  Coehabamba,  Bolivia,  at  10,000 
feet  (3,050  m.) ;  at  Crucero  Alto  in  southern  Peru  at  14,600  feet 


TIOE"  OF  193 


^Wi 


KUometeiti 


N 


li 


THE  PERUVIAN  LANDSCAPE 


I5,000'_ 

10,000: 

5,000! 


SfA  LEVEL 


SEA  L5l/eL 


15.000' 

~~-~"7 

^^              _.-—'' "^10,000- 

...8a 

■--^     .^^^     h.  .■■■■■"   ^■''°°'- 

o             o 

■" ■ ci"              o. 

—                      LO 
1                           1 

Fig.  127 — Topographic  profiles  across  typical  valleys  of  southern  Peru.  They  are 
drawn  to  scale  and  the  equality  of  gradient  of  the  gentler  upper  slopes  is  so  close  that 
almost  any  curve  would  serve  as  a  composite  of  the  whole.  These  curves  form  the 
basis  of  the  diagram,  Fig.  128,  whereby  the  amount  of  elevation  of  the  Andes  in  late 
geologic  time  may  be  determined.  The  approximate  locations  of  the  profiles  are  as 
follows:  1,  Antabamba;  2,  Chuquibambilla;  3,  upland  south  of  Antabamba;  4,  Apurimac 
Canyon  above  Pasaje;  5,  Abancay;  6,  Arma  (Cordillera  Vilcapampa)  ;  7,  divide  above 
Huancarama;  8,  Huascatay;  9,  Huascatay,  farther  downstream;  10,  Rio  Pampas.  The 
upper  valley  in  8  is  still  undissected;  7  is  practically  the  same;  8a  is  at  the  level 
which  8  must  reach  before  its  side  slopes  are  as  gentle  as  at  the  end  of  the  preceding 
interrupted   cycle. 

(4,450  m.) ;  several  hundred  miles  farther  north  at  Anta  near 
Cuzco,  11,000  feet  to  12,000  feet  (3,600  to  3,940  m.),  and  Fig.  129 
shows  typical  conditions  in  the  Vilcabamba  Valley  along  the  route 
of  the  Yale  Peruvian  Expedition  of  1911.  The  characteristic 
slopes  so  clearly  represented  in  these  four  photographs  are  the 
most  persistent  topographic  elements  in  the  physiography  of  the 
Central  Andes. 


190  THE  ANDES  OF  SOUTHERN  PERU 

The  rock  masses  upon  which  the  mature  slopes  were  formed 
range  from  soft  to  hard,  from  stratified  shales,  slates,  sandstones, 
conglomerates,  and  limestones  to  volcanics  and  intrusive  granites. 
While  these  variations  impose  corresponding  differences  of  form, 
the  graded  quality  of  the  slopes  is  rarely  absent.  In  some  places 
the  highly  inclined  strata  are  sho^^^l  thinly  veiled  with  surface 
debris,  yet  so  even  as  to  appear  artificially  graded.  The  rock  in 
one  place  is  hard  granite,  in  another  a  moderately  hard  series  of 
lava  flows,  and  again  rather  weak  shales  and  sandstones. 

Proof  of  the  rapid  and  great  uplift  of  certain  now  lofty  moun- 
tain ranges  in  late  geologic  time  is  one  of  the  largest  contribu- 
tions of  physiography  to  geologic  history.  Its  validity  now  rests 
upon  a  large  body  of  diversified  evidence.  In  1907  I  crossed  the 
Cordillera  Sillilica  of  Bolivia  and  northern  Chile  and  came  upon 
clear  evidences  of  recent  and  great  uplift.  The  conclusions  pre- 
sented at  that  time  were  tested  in  the  region  studied  in  1911,  500 
miles  farther  north,  with  the  result  that  it  is  now  possible  to  state 
more  precisely  the  dates  of  origin  of  certain  prominent  topo- 
graphic forms,  and  to  reconstruct  the  conditions  which  existed 
before  the  last  great  uplift  in  which  the  Central  Andes  were  born. 
The  relation  to  this  general  problem  of  the  forms  under  discus- 
sion will  now  be  considered. 

The  gradients  of  the  mature  slopes,  as  we  have  already  seen, 
are  distinctly  moderate.  In  the  Anta  region,  over  an  area  several 
hundred  square  miles  in  extent,  they  run  from  several  degrees  to 
20°  or  30°.  Ten-degree  slopes  are  perhaps  most  common.  If  the 
now  dissected  slopes  be  reconstructed  on  the  basis  of  many 
clinometer  readings,  pliotographs,  and  topographic  maps,  the  re- 
sult is  a  series  of  profiles  as  in  Fig.  127.  If,  furtlior,  the  restored 
slopes  be  coordinated  over  an  extensive  area  the  gradients  of  the 
resulting  valley  floors  will  run  from  3°  to  10°.  Finally,  if  these 
valley  floors  be  extended  westward  to  the  Pacific  and  eastward 
to  the  Amazon  basin,  they  will  be  found  about  5,000  feet  above 
sea  level  and  4,000  feet  above  the  eastern  plains.  (For  explana- 
tion of  method  and  data  employed,  see  the  accompanying  figures 
127-128).    It  is,  therefore,  a  justifiable  conclusion  that  since  the 


THE  PERUVIAN  LANDSCAPE 


191 


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192  THE  ANDES  OF  SOUTHERN  PERU 

formation  of  the  slopes  the  Andes  have  been  uplifted  at  least  a 
mile,  or,  to  put  it  in  another  way,  the  Andes  at  the  time  of  forma- 
tion of  the  mature  slopes  were  at  least  a  mile  lower  than  thej  are 
at  present. 

Further  proof  of  recent  and  great  uplift  is  afforded  by  the 
deeply  intrenched  streams.  After  descending  the  long  graded 
slopes  one  comes  upon  the  cliffed  canyons  with  a  feeling  of  con- 
sternation. The  etfect  of  powerful  erosion,  incident  upon  uplift, 
is  heightened  by  the  ungraded  character  of  the  river  bed.  Falls 
and  rapids  abound,  the  river  profiles  suggest  tumultuous  descents, 
and  much  time  ^yi[\  elapse  before  the  river  beds  have  the  regular 
and  moderate  gradients  of  the  streams  draining  the  mature  sur- 
face before  uplift  as  shown  in  the  profiles  by  the  dotted  lines  rep- 
resenting the  restored  valley  floors  of  the  older  cycle.  Since  the 
smooth-contoured  landscape  was  formed  great  changes  have  taken 
place.  The  streams  have  changed  from  completely  graded  to  al- 
most completely  ungraded  profiles;  in  place  of  a  subdued  land- 
scape we  now  have  upland  slopes  intersected  by  mile-deep  can- 
yons; the  high-level  slopes  could  not  have  been  formed  under 
existing  conditions,  for  they  are  being  dissected  by  the  present 
streams. 

Since  the  slopes  of  the  land  in  general  undergo  progressive 
changes  in  the  direction  of  flatter  gradients  during  a  given  geo- 
graphical cycle,  it  follows  that  with  the  termination  of  one  cycle 
and  the  beginning  of  another,  two  sets  of  slopes  will  exist  and  that 
the  gradients  of  the  two  will  bo  unlike.  The  result  is  a  break  in 
the  descent  of  the  slopes  from  high  to  low  levels  to  which  the  name 
** topographic  unconformity"  is  now  applied.  It  will  be  a  promi- 
,  nent  feature  of  the  landscape  if  tlie  higher,  older,  mid  ilatter  gradi- 
lents  have  but  little  declivity,  and  the  gradients  of  the  lower 
younger  slopes  are  very  steep,  lii  those  ])l;u'os  where  tlie  i-elief 
of  the  first  cycle  was  still  great  at  the  time  of  uplift,  the  erosion 
forms  of  the  second  cycle  may  not  be  differentiated  from  those  of 
the  first,  since  both  are  mjirked  by  steep  gradients.  Tn  the  Cen- 
tral Andes  the  change  in  gradient  between  the  higher  and  lower 
slopes  is  generally  well  marked.     It  occurs  at  variable  heights 


CDITI 
lECT 


iA-°50 


J 


'•^' 


THE  PERUVIAN  LANDSCAPE  193 

above  the  valley  floors,  though  rarely  more  than  3,000  feet  above\ 
them.    In  the  more  central  tracts,  far  from  the  main  streams  and  \ 
their  associated  canyons,  dissection  in  the  present  erosion  cycle 
has  not  yet  been  initiated^  the  mature  slopes  are  still  intact,  and  / 
a  topographic  unconformity  has  not  yet  been  developed.     The 
higher  slopes  are  faced  with  rock  and  topped  with  slowly  moving 
waste.    Ascent  of  the  spur  end  is  by  steep  zigzag  trails ;  once  the\ 
top  is  gained  the  trail  runs  along  the  gentler  slopes  without  spe-j 
cial  difficulties. 

It  is  worth  noting  at  this  point  that  the  surface  of  erosion  still 
older  than  the  mature  slopes  herewith  described  appears  not  to 
have  been  developed  along  the  seventy-third  meridian  of  Peru,  or 
if  developed  at  one  time,  fragments  of  it  no  longer  remain.  The 
last  well-developed  remnant  is  southwest  of  Cuzco,  Fig.  130.  I 
have  elsewhere  described  the  character  and  geographic  distribu- 
tion of  this  oldest  recognizable  surface  of  the  Central  Andes. ^ 
Southern  Peru  and  Bolivia  and  northern  Chile  display  its  features 
in  what  seems  an  unmistakable  manner.  The  best  locality  yet  found 
is  in  the  Desaguadero  Valley  between  Ancoaqui  and  Concordia. 
There  one  may  see  thousands  of  feet  of  strongly  inclined  sedi- 
ments of  varying  resistance  beveled  by  a  well-developed  surface 
of  erosion  whose  preserval  is  owing  to  a  moderate  rainfall  and  to 
location  in  an  interior  basin.- 

The  highest  surface  of  a  region,  if  formed  during  a  prolonged 
period  of  erosion,  becomes  a  surface  of  reference  in  the  determina- 
tion of  the  character  and  amount  of  later  crustal  deformations, 
having  somew^hat  the  same  functions  as  a  key  bed  in  stratigraphic 
geology.  Indeed,  concrete  physiographic  facts  may  be  the  only 
basis  for  arguments  as  to  both  epeirogenic  and  orogenic  move- 
ments. The  following  considerations  may  show  in  condensed  form- 
the  relative  value  of  physiographic  evidence : 

1.    If  movements  in  the  earth's  crust  are  predominantly  clotcn- 


*  The  Physiography  of  the  Central  Andes,  Am.  Journ.  Sci.,  Vol.  40,  1909,  pp.  197-217 
and  373-402. 

°  Results  of  an  Expedition  to  the  Central  Andes,  Bull.  Am.  Geog.  Soc..  Vol.  46,  1914. 
Figs.  28  and  29. 


194.  THE  ANDES  OF  SOUTHERN  PERU 

ward,  sedimentation  may  be  carried  on  continuously  and  a  clear 
geologic  record  may  be  made. 

2.  Even  if  crustal  movements  are  alternatelj^  downward  and 
upward,  satisfactory  conclusions  may  be  drawn  from  both  (a)  the 
nature  of  the  buried  surfaces  of  erosion,  and  (b)  the  alternating 
character  of  the  sediments. 

3.  If,  however,  the  deformative  processes  effect  steady  or  in- 
termittent uplifts,  there  may  be  no  sediments,  at  least  within  the 
limits  of  the  positive  crustal  units,  and  a  geologic  record  must  be 
derived  not  from  sedimentary  deposits  but  from  topographic 
forms.  We  speak  of  the  lost  intervals  represented  by  strati- 
graphic  breaks  or  unconformities  and  commonly  emphasize  our 
ignorance  concerning  them.  The  longest,  and,  from  the  human 
standpoint,  the  most  important,  break  in  the  sedimentary  record 
is  that  of  the  present  wherever  degradation  is  the  predominant 
physiographic  process.  Unlike  the  others  the  lost  interval  of  the 
present  is  not  lost,  if  we  may  so  put  it,  but  is  in  our  possession, 
and  may  be  definitely  described  as  a  concrete  thing.  It  is  the 
physiography  of  today. 

Even  where  long-buried  surfaces  of  erosion  are  exposed  to 
view,  as  in  northern  Wisconsin,  where  the  Pre-Cambrian  paleo- 
plain  projects  from  beneath  the  Paleozoic  sediments,  or,  as  in  New 
Jersey  and  southeastern  Pennsylvania,  where  the  surface  devel- 
oped on  the  crystalline  rocks  became  by  depression  the  floor  of  the 
Triassic  and  by  more  recent  uplift  and  erosion  has  been  exposed 
to  view, — even  in  such  cases  the  exposures  are  of  small  extent  and 
give  us  at  best  but  meager  records.  In  short,  many  of  the  breaks 
in  the  geologic  record  are  of  such  long  duration  as  to  make  im- 
perative the  use  of  physiographic  principles  and  methods.  The 
great  Appalachian  System  of  eastern  North  America  has  been  a 
land  area  practically  since  tlio  end  of  Iho  Paleozoic.  In  the  Cen- 
tral Andes  the  "lost  interval,"  from  tlie  standpoint  of  llio  sedi- 
mentary record,  dates  from  11  lo  close  of  the  Cretaceous,  except  in 
a  few  local  intermont  basins  partially  filled  with  Tertiary  or 
Pleistocene  deposits.  Physiographic  interpretations,  therefore, 
serve  the  double  purpose  of  supplying  a  part  of  the  geologic  rec- 


THE  PERUVIAN  LANDSCAPE  195 

ord  while  at  the  same  time  forming  a  basis  for  the  scientific  study 
of  the  surface  distribution  of  living  forms. 

The  geologic  dates  of  origin  of  the  principal  topographic  forms 
of  the  Central  Andes  may  be  determined  with  a  fair  degree  of 
accuracy.  Geologic  studies  in  Peru  and  Bolivia  have  emphasized 
the  wide  distribution  of  the  Cretaceous  formations.  They  consist 
principally  of  thick  limestones  above  and  sandstones  and  con- 
glomerates below,  and  thus  represent  extensive  marine  submer- 
gence of  the  earth's  crust  in  the  Cretaceous  where  now  there  are 
very  lofty  mountains.  The  Cretaceous  deposits  are  everywhere 
strongly  deformed  or  uplifted  to  a  great  height,  and  all  have  been 
deeply  eroded.  They  were  involved,  together  with  other  and  much 
older  sediments,  in  the  erosion  cycle  which  resulted  in  the  devel- 
opment of  the  widely  extended  series  of  mature  slopes  already 
described.  From  low  scattered  island  elevations  projecting  above 
sea  level,  as  in  the  Cretaceous  period,  the  Andes  were  transformed 
by  compression  and  uplift  to  a  rugged  mountain  belt  subjected 
to  deep  and  powerful  erosion.  The  products  of  erosion  were  in 
part  swept  into  the  adjacent  seas,  in  part  accumulated  on  the 
floors  of  intermont  basins,  as  in  the  great  interior  basins  of  Titi- 
caca  and  Poopo. 

Since  the  early  Tertiary  strata  are  themselves  deformed  from 
once  simple  and  approximately  horizontal  structures  and  sub- 
jected to  moderate  tilting  and  faulting,  it  follows  that  mountain- 
making  movements  again  affected  the  region  during  later  Terti-  ^ 
ary.  They  did  not,  however,  produce  extreme  effects.  They  did 
stimulate  erosion  and  bring  about  a  reorganization  of  all  the  / 
slopes  with  respect  to  the  new  levels. 

This  agrees  closely  with  a  second  line  of  evidence  which  rests 
upon  an  independent  basis.  The  alluvial  fill  which  lies  upon  all  the 
canyon  and  valley  floors  is  of  glacial  origin,  as  sho^wTi  by  its  inter- 
locking relations  with  morainal  deposits  at  the  valley  heads.  It  is 
now  in  process  of  dissection  and  since  its  deposition  in  the  Pleis- 
tocene had  been  eroded  on  the  average  about  200  feet.  Clearly, 
to  form  a  3,000-foot  canyon  in  hard  rock  requires  much  more  time 
than  to  deposit  and  again  partially  to  excavate  an  alluvial  fill  sev- 


196  THE  ANDES  OF  SOUTHERN  PERU 

eral  hundred  feet  deep.  Moreover,  the  glacial  material  is  coarse 
throughout,  and  was  built  up  rapidly  and  dissected  rapidly.  In 
most  cases,  furthermore,  coarse  material  at  the  bottom  of  the  gla- 
cial series  rests  directly  upon  the  rock  of  a  narrow  and  ungraded 
valley  floor.  From  these  and  allied  facts  it  is  concluded  that  there 
is  no  long  time  interval  represented  by  the  transitions  from  de- 
grading to  aggrading  processes  and  back  again.  The  early  Pleisto- 
cene, therefore,  seems  quite  too  short  a  period  in  which  to  produce 
the  bold  forms  and  effect  the  deep  erosion  which  marks  the  period 
between  the  close  of  the  mature  cycle  and  the  beginnings  of  deposi- 
tion in  the  Pleistocene. 

j  The  alternative  conclusion  is  that  the  greater  part  of  the  canyon 
/cutting  was  effected  in  the  late  Tertiary,  and  that  it  continued  into 
the  early  Pleistocene  until  further  erosion  was  halted  by  changed 
climatic  conditions  and  the  augmented  delivery  of  land  waste  to 
all  the  streams.  The  final  development  of  the  well-graded  high- 
level  slopes  is,  therefore,  closely  confined  to  a  small  portion  of  the 
Tertiary.  The  closest  estimate  which  the  facts  support  appears 
to  be  Miocene  or  early  Pliocene.  It  is  clear,  however,  that  only  the 
culmination  of  the  period  can  be  definitely  assigned.  Erosion  was 
in  full  progress  at  the  close  of  the  Cretaceous  and  by  middle 
Tertiary  had  effected  vast  changes  in  the  landscape.  The  Tertiary 
strata  are  marked  by  coarse  basal  deposit  and  by  thin  and  very 
fine  top  deposits.  Though  their  deformed  condition  indicates  a 
period  of  crustal  disturbance,  the  Tertiary  beds  give  no  indica- 
tion of  wholesale  transformations.  They  indicate  chiefly  tilting 
and  moderate  and  normal  faulting.  Tlie  previously  developed  ef- 
fects of  erosion  were,  therefore,  not  radically  modified.  The  sur- 
face was  thus  in  large  measure  prepared  by  erosion  in  the  early 
Tertiary  for  its  final  condition  of  maturity  reached  during  the 
early  Pliocene. 

It  seems  appropriate,  in  concluding  this  chapter,  to  summarize 
in  its  main  outlines  the  physiography  of  southern  Peru,  partly  to 
condense  the  extended  discussion  of  the  preceding  paragraphs, 
and  partly  to  sui)ply  a  background  for  the  three  chapters  that 
follow.    The  outstanding  features  are  broad  plateau  areas  sepa- 


THE  PERUVIAN  LANDSCAPE  197 

rated  by  well-defined  "Cordilleras."  The  plateau  divisions  are 
not  everywhere  of  the  same  origin.  Those  southwest  of  Cuzco 
(Fig.  130),  and  in  the  Anta  Basin  (Fig.  124),  northwest  of  Cuzco,  J 
are  due  to  prolonged  erosion  and  may  be  defined  as  peneplane 
surfaces  uplifted  to  a  great  height.  They  are  now  bordered  on 
the  one  hand  by  deep  valleys  and  troughs  and  basins  of  erosion 
and  deformation;  and,  on  the  other  hand,  by  residual  elevations 
that  ow^e  their  present  topography  to  glacial  erosion  superim- 
posed upon  the  normal  erosion  of  the  peneplane  cycle.  The 
residuals  form  true  mountain  chains  like  the  Cordillera  Vilcanota 
and  Cordillera  Vilcapampa;  the  depressions  due  to  erosion  or 
deformation  or  both  are  either  basins  like  those  of  Anta  and 
Cuzco  or  valleys  of  the  canyon  type  like  the  Urubamba  canyon; 
the  plateaus  are  broad  rolling  surfaces,  the  punas  of  the  Peruvian 
Andes. 

There  are  two  other  types  of  plateaus.  The  one  represents  a 
mature  stage  in  the  erosion  cycle  instead  of  an  ultimate  stage ;  the 
other  is  volcanic  in  origin.  The  former  is  best  developed  about 
Antabamba  (Figs.  122  and  123),  where  again  deep  canyons  and 
residual  ranges  form  the  borders  of  the  plateau  remnants.  The 
latter  is  well  developed  above  Cotahuasi  and  in  its  simplest  form 
is  represented  in  Fig.  133.  Its  surface  is  the  top  of  a  vast  accumu- 
lation of  lavas  in  places  over  a  mile  thick.  While  rough  in  detail 
it  is  astonishingly  smooth  in  a  broad  view  (Fig.  29).  Above  it 
rise  two  types  of  elevations :  first,  isolated  volcanic  cones  of  great 
extent  surrounded  by  huge  lava  flows  of  considerable  relief;  and 
second,  discontinuous  lines  of  peaks  where  volcanic  cones  of  less 
extent  are  crowded  closely  together.  The  former  type  is  displayed 
on  the  Coropuna  Quadrangle,  the  latter  on  the  Cotahuasi  and  La 
Cumbre  Quadrangles. 

So  high  is  the  elevation  of  the  lava  plateau,  so  porous  its  soil, 
so  dry  the  climate,  that  a  few  through-flowing  streams  gather  the 
drainage  of  a  vast  territory  and,  as  in  the  Grand  Canyon  country 
of  our  West,  they  have  at  long  interv^als  cut  profound  canyons. 
The  Arma  has  cut  a  deep  gorge  at  Salamanca;  the  Cotahuasi  runs 
in  a  canyon  in  places  7,000  feet  deep ;  the  Majes  heads  at  the  edge    \j 


198  THE  ANDES  OF  SOUTHERN  PERU 

of  the  volcanic  field  in  a  steep  amphitheatre  of  majestic  propor- 
tions. 

Finally,  we  have  the  plateaus  of  the  coastal  zone.  These  are 
plains  with  surfaces  several  thousand  feet  in  elevation  separated 
by  gorges  several  thousand  feet  deep.  The  Pampa  de  Sihuas  is  an 
illustration.  The  post-maturely  dissected  Coast  Range  separates 
it  from  the  sea.  The  pampas  are  in  general  an  aggradational 
product  formed  in  a  past  age  before  uplift  initiated  the  present 
canyon  cycle  of  erosion.  Other  plateaus  of  the  coastal  zone  are 
erosion  surfaces.  The  Tablazo  de  lea  appears  to  be  of  this  type. 
That  at  Arica,  Chile,  near  the  southern  boundary  of  Peru,  is 
demonstrably  of  this  type  with  a  border  on  which  marine  plana- 
tion  has  in  places  given  rise  to  a  broad  terrace  effect.^ 


*The  Physiography  of  the  Central  Andes,  by  Isaiah  Bowman;  Am.  Journ.  Sci.,  Vol. 
28,  1909,  pp.  197-217  and  373-402.     See  especially,  ibid.,  Fig.  11,  p.  216. 


FiCi.    129. 


Fig.    l.JU. 


Fig.  129 — Composition  of  slopes  at  Puquiura,  Vilcabamba  Valley,  elevation  9,000 
feet  (2,740  m. ).  The  second  prominent  spur  entering  the  valley  on  the  left  has  a 
flattish  top  unrelated  to  the  rock  structure.  Like  the  spurs  on  the  riglit  its  blunt  end 
and  flat  top  indicate  an  earlier  erosion  cycle  at  a  lower  elevation. 

Fig.  130 — Inclined  Paleozoic  strata  truncated  I)y  an  undulating  surface  of  erosion 
at  15,000  feet,  southwest  of  Cuzco. 


I'iri.   l.'H      'IVrriiccd  valley  nlopcH  at    Iluayiiacolas,  Cotalmasi   X'allcy, 
(3,r)()()  III.).     Solimanii  is  in  the  l)iickf,'niiiii(l      <  >ii  llir'  lldoi  of  IIh'  (  (il;ilni;i' 
tri'OH  grow.     At  IIiiaynacotaH  roni  and  pdtatdcs  air  llii'  rhic  I    inndiicts. 
compoHt'd  almoHt  entirely  of  lava.      I  licrc  arc  over  a    Iniiidrrd   mainr  IJn 
5,000   to    7,000    feet   thick. 


at 
i  (a 


I  l,:)(l((  fccL 

iiyoii  fruit 

Hoction  is 

ggregating 


CHAPTER  XII 

THE    WESTERN    ANDES:     THE     MARITIME     CORDILLERA 
OR  CORDILLERA  OCCIDENTAL 

The  Western  or  Maritime  Cordillera  of  Peru  forms  part  of 
the  great  volcanic  field  of  South  America  which  extends  from 
Argentina  to  Ecuador.  On  the  walls  of  the  Cotahuasi  Canyon 
(Fig.  131),  there  are  exposed  over  one  hundred  separate  lava 
flows  piled  7,000  feet  deep.  They  overflowed  a  mountainous  relief, 
completely  burying  a  limestone  range  from  2,000  to  4,000  feet 
high.  Finally,  upon  the  surface  of  the  lava  plateau  new  moun- 
tains were  formed,  a  belt  of  volcanoes  5,000  feet  (1,520  m.)  high 
and  from  15,000  to  20,000  feet  (4,570  to  6,100  m.)  above  the  sea. 
There  were  vast  mud  flows,  great  showers  of  lapilli,  dust,  and 
ashes,  and  w^ith  these  violent  disturbances  also  came  many  changes 
in  the  drainage.  Sixty  miles  northeast  of  Cotahuasi  the  outlet  of 
an  unnamed  deep  valley  was  blocked,  a  lake  was  formed,  and  sev- 
eral hundred  feet  of  sediments  were  deposited.  They  are  now 
wasting  rapidly,  for  they  lie  in  the  zone  of  alternate  freezing  and 
thawing,  a  thousand  feet  and  more  below  the  snowline.  Some  of 
their  bad-land  forms  look  like  the  solid  bastions  of  an  ancient 
fortress,  while  others  have  the  delicate  beauty  of  a  Japanese 
temple. 

Not  all  the  striking  effects  of  vulcanism  belong  to  the  remote 
geologic  past.  A  day's  journey  northeast  of  Huaynacotas  are  a 
group  of  lakes  only  recently  hemmed  in  by  flows  from  the  small 
craters  thereabouts.  The  fires  in  some  volcanic  craters  of  the 
Peruvian  Andes  are  still  active,  and  there  is  no  assurance  that 
devastating  flows  may  not  again  inundate  the  valleys.  In  the 
great  Pacific  zone  or  girdle  of  volcanoes  the  earth's  crust  is  yet 
so  unstable  that  earthquakes  occur  every  year,  and  at  intervals  of 
a  few  years  they  have  destructive  force.  Cotahuasi  was  greatly 
damaged  in  1912;  Abancay  is  shaken  every  few  years;  and  the 
violent  earthquakes  of  Cuzco  and  Arequipa  are  historic. 

199 


200  THE  ANDES  OF  SOUTHERN  PERU 

On  the  eastern  margin  of  the  volcanic  country  the  flows  thin 
out  and  terminate  on  the  summit  of  a  limestone  (Cretaceous) 
plateau.  On  the  western  margin  they  descend  steeply  to  the  nar- 
row west-coast  desert.  The  greater  part  of  the  lava  dips  beneath 
the  desert  deposits;  there  are  a  few  intercalated  flows  in  the 
deposits  themselves,  and  the  youngest  flows — limited  in  number — 
have  extended  do^vn  over  the  inner  edge  of  the  desert. 

The  immediate  coast  of  southern  Peru  is  not  volcanic.  It  is 
composed  of  a  very  hard  and  ancient  granite-gneiss  which  forms 
a  narrow  coastal  range  (Fig.  171).  It  has  been  subjected  to  very 
long  and  continued  erosion  and  now  exhibits  mature  erosion  forms 
of  great  uniformity  of  profile  and  declivity. 

From  the  outcrops  of  older  rocks  beneath  the  lavas  it  is  pos- 
sible to  restore  in  a  measure  the  pre-volcanic  topography  of  the 
Maritime  Cordillera.  In  its  present  altitude  it  ranges  from  several 
thousand  to  15,000  feet  above  sea  level.  The  unburied  topography 
has  been  smoothed  out;  the  buried  topography  is  rough  (Figs.  29 
and  166).  The  contact  lines  between  lavas  and  buried  surfaces  in 
the  deep  Majes  and  Cotahuasi  valleys  are  in  places  excessively 
serrate.  From  this,  it  seems  safe  to  conclude  that  the  period  of 
\nilcanism  was  so  prolonged  that  great  changes  in  the  unburied 
relief  were  effected  by  the  agents  of  erosion.  Thus,  while  the 
dominant  process  of  volcanic  upbuilding  smoothed  the  former 
rough  topography  of  the  Maritime  Cordillera,  erosion  likewise 
measurably  smoothed  the  present  high  extra-volcanic  relief  in  the 
central  and  eastern  sections.  The  effect  has  been  to  develop  a 
broad  and  sufliciently  smooth  aspect  to  the  summit  topography  of 
the  entire  Andes  to  give  them  a  plateau  character.  Afterward  the 
whole  mountain  region  was  uplifted  about  a  mile  above  its  former 
level  so  that  at  present  it  is  also  continuously  lofty. 

Tlie  zone  of  most  intense  volcanic  action  does  not  coincide  with 
tlic  liighest  part  of  ilic  pro-volcauic  topography.  If  the  pro-vol- 
canic relief  were  even  in  a  very  general  way  like  that  which  would 
be  exhibited  if  the  lavas  were  now  removed,  wo  should  have  to  say 
that  the  chief  volcanic  outbursts  took  place  on  tho  western  flank 
of  an  old  and  deeply  dissected  limestone  range. 


WESTERN  ANDES:  MARITIME  CORDILLERA  201 

The  volume  of  the  lavas  is  enormous.  They  are  a  mile  and  a 
half  thick,  nearly  a  hundred  miles  wide,  and  of  indefinite  extent 
north  and  south.  Their  addition  to  the  Andes,  therefore,  has 
greatly  broadened  the  zone  of  lofty  mountains.  Their  passes  are 
from  2,000  to  3,000  feet  higher  than  the  passes  of  the  eastern 
Andes.  They  have  a  much  smaller  number  of  valleys  sufficiently 
deep  to  enjoy  a  mild  climate.  Their  soil  is  far  more  porous  and 
dry.  Their  vegetation  is  more  scanty.  They  more  than  double 
the  difficulties  of  transportation.  And,  finally,  their  all  but  un- 
populated loftier  expanses  are  a  great  vacant  barrier  between 
farms  in  the  warm  valleys  of  eastern  Peru  and  the  ports  on  the 
west  coast. 

The  upbuilding  process  was  not,  of  course,  continuous.  There 
were  at  times  intervals  of  quiet,  and  some  of  them  were  long 
enough  to  enable  streams  to  become  established.  Buried  valleys 
may  be  observed  in  a  number  of  places  on  the  canyon  walls,  where 
subsequently  lava  flows  displaced  the  streams  and  initiated  new 
drainage  systems.  In  these  quiet  intervals  the  weathering  agents 
attacked  the  rock  surfaces  and  formed  soil.  There  were  at  least 
three  or  four  such  prolonged  periods  of  weathering  and  erosion 
wherein  a  land  surface  was  exposed  for  many  thousands  of  years, 
stream  systems  organized,  and  a  cultivable  soil  formed.  No  evi- 
dence has  been  found,  however,  that  man  was  there  to  cultivate 
the  soil. 

The  older  valleys  cut  in  the  quiet  period  are  mere  pygmies  be- 
side the  giant  canyons  of  today.  The  present  is  the  time  of  domi- 
nant erosion.  The  forces  of  vulcanism  are  at  last  relatively  quiet. 
Recent  flows  have  occurred,  but  they  are  limited  in  extent  and  in 
effects.  They  alter  only  the  minor  details  of  topography  and 
drainage.  "Were  it  not  for  the  oases  set  in  the  now  deep-cut  can- 
yon floors,  the  lava  plateau  of  the  Maritime  Cordillera  would 
probably  be  the  greatest  single  tract  of  unoccupied  volcanic  coun- 
try in  the  world. 

The  lava  plateau  has  been  dissected  to  a  variable  degree.  Its 
high  eastern  margin  is  almost  in  its  original  condition.  Its  west- 
ern margin  is  only  a  hundred  miles  from  the  sea,  so  that  the 


202  THE  ANDES  OF  SOUTHERN  PERU 

streams  have  steep  gradients.  In  addition,  it  is  lofty  enough  to 
have  a  moderate  rainfall.  It  is,  therefore,  deeply  and  generally 
dissected.  Within  the  borders  of  the  plateau  the  degree  of  dissec- 
tion depends  chiefly  upon  position  with  respect  to  the  large 
streams.  These  were  in  turn  located  in  an  accidental  manner. 
The  repeated  upbuilding  of  the  surface  by  the  extensive  outflow 
of  liquid  rock  obliterated  all  traces  of  the  earlier  drainage.  In  the 
Cotahuasi  Canyon  the  existing  stream,  working  down  through  a 
mile  of  lavas,  at  last  uncovered  and  cut  straight  across  a  moun- 
tain spur  2,000  feet  high.  Its  course  is  at  right  angles  to  that 
pursued  by  the  stream  that  once  drained  the  spur.     It  is  note- 

( worthy  that  the  Cotahuasi  and  adjacent  streams  take  northerly 
courses  and  join  Atlantic  rivers.  The  older  drainage  was  directly 
west  to  the  Pacific.  Thus,  vulcanism  not  only  broadened  the 
Andes  and  increased  their  height,  but  also  moved  the  continental 
divide  still  nearer  the  west  coast. 
V  . 

IThe  glacial  features  of  the  western  or  Maritime  Cordillera  are 
of  small  extent,  partly  because  vulcanism  has  added  a  considera- 
ble amount  of  material  in  post-glacial  time,  partly  because  the  cli- 
mate is  so  exceedingly  dry  that  the  snowline  lies  near  the  top  of 
the  country.  The  slopes  of  the  volcanic  cones  are  for  the  most 
part  deeply  recessed  on  the  southern  or  shady  sides.  Above  17,500 
feet  (5,330  m.)  the  process  of  snow  and  ice  excavation  still  con- 
tinues, but  the  tracts  that  exceed  this  elevation  are  confined  to  the 
loftiest  peaks  or  their  immediate  neighborhood.  There  is  a  dis- 
tinct difference  between  the  glacial  forms  of  the  eastern  or  moister 
and  the  western  or  dryor  flanks  of  this  Cordillera.  Only  peaks 
like  Coropuna  and  Solimana  near  the  western  border  now  bear  or 
ever  bore  snowfields  and  glaciers.  By  coiitrnst  the  eastern  aspect 
is  h(,'a\ily  glaciat(Hl.  On  I^a  Cumbro  (^)nji(lraiigle,  there  is  a  huge 
glacial  trougli  at  10,000  feet  (4,87()  m.),  and  tliis  extouds  with  rami- 
ficalioiis  up  into  tlic  siiowfields  tlial  f'oiMiici'ly  iucliidcd  llic  liiglicst 
countiy.  Prolonged  ulacial  erosion  i)roduced  a  Cull  set  of  topo- 
graphic forms  cliaract{!ristic  of  the  work  of  Alpine  glaciers.  Thus, 
caeh  ()'[  the  main  mountain  chains  that  make  up  the  Andean  sys- 
tem has,  like  the  system  as  a  whole,  a  relatively  more-dry  and  a 


L 


WESTERN  ANDES:  MARITIME  CORDILLERA  203 

relatively  less-dry  aspect.  The  snowline  is,  therefore,  canted 
from  west  to  east  on  each  chain  as  well  as  on  the  system.  How- 
ever, this  effect  is  combined  with  a  solar  effect  in  an  unequal  way. 
In  the  driest  places  the  solar  factor  is  the  more  efficient  and  the 
snowline  is  there  canted  from  north  to  south. 


CHAPTER  XIII 

THE    EASTERN    ANDES:    THE    CORDILLERA    VILCAPAMPA 

The  culminating  range  of  tlie  eastern  Andes  is  the  so-ealled 
Cordillera  Vilcapampa.  Its  numerous,  sharp,  snow-covered  peaks 
are  visible  in  every  summit  view  from  the  central  portion  of  the 
Andean  system  almost  to  the  western  border  of  the  Amazon  basin. 
Though  the  range  forms  a  water  parting  nearly  five  hundred  miles 
long,  it  is  crossed  in  several  places  by  large  streams  that  flow 
through  deep  canyons  bordered  by  precipitous  cliffs.  The  Uru- 
bamba  between  Torontoy  and  Colpani  is  the  finest  illustration. 
For  height  and  ruggedness  the  Vilcapampa  mountains  are  among 
the  most  noteworthy  in  Peru.  Furthermore,  they  display  glacial 
features  on  a  scale  unequaled  elsewhere  in  South  America  north 
of  the  ice  fields  of  Patagonia. 

GLACIERS    AND    GLACIAX.   FORMS 

One  of  the  most  impressive  sights  in  South  America  is  a 
tropical  forest  growing  upon  a  glacial  moraine.  In  many  places 
in  eastern  Bolivia  and  Peru  the  glaciers  of  the  Ice  Age  were  from 
5  to  10  miles  long — almost  the  size  of  the  Mer  de  Glace  or  the 
famous  Rhone  glacier.  In  the  Juntas  Valley  in  eastern  Bolivia 
the  tree  line  is  at  10,000  feet  (3,050  m.),  but  the  terminal  moraines 
lie  several  thousand  feet  lower.  In  eastern  Peru  the  glaciers  in 
many  places  extended  down  nearly  to  the  tree  line  and  in  a  few 
places  well  below  it.  In  the  Cordillera  Vilcapampa  vast  snow- 
fields  and  glacier  systems  were  spread  out  over  a  summit  area 
as  broad  as  the  Southern  Appalachians.  Tlio  snowfields  have 
since  shrunk  to  the  higher  mountain  recesses;  the  glaciers  have 
retreated  for  the  most  part  to  the  valley  heads  or  the  cirque 
floors;  and  the  lower  limit  of  perpetual  snow  has  been  raised  to 
15,500  feet. 

201 


Fig.   132. 


Fig.   l; 


Fig.  132 — Recessed  volcanoes  in  the  right  background  and  eroded  tuffs,  ash  beds, 
and  lava  flows  on  the  left.    Maritime  Cordillera  above  Cotahuasi. 

Fig.  133 — The  summit  of  the  great  lava  plateau  above  Cotahuasi  on  the  trail  to 
Antabamba.  The  lavas  are  a  mile  and  a  half  in  thickness.  The  elevation  is  16,000 
feet.  Hence  the  volcanoes  in  the  background,  17,000  feet  above  sea  level,  are  mere 
hills  on  the  surface  of  the  lofty  plateau. 


Fig.  134. 


Fi(i.   ):{"). 


Fk;.    1.'{4 — SouthwcHtcrn    iiH|)cct    c,f  the    CnKlillcr;!    \  il(:i|);mii):i    Ipctwcni    AiilM    iuid 

rruhainhti  from  Lake  Iluiiipo.  HiiKKi'd  siiiniiiit,  t(i|i<>;,'iiiiili>  in  tlir  Ipiick^^'ioimd,  graded 
jiDHt-matiiro  hIoju-h  in  the  middle  di.Htaiicc,  and  Holiition  jjikr  in  linii^toMc  in  liu-  fore- 
ground. 

Fio.  l.'{5— Snmmit  view,  Cordill-Ta  \iic;i|(:nn|i^i.  'I'Imtc  :irc'  liltrcn  ^'hicicrs  repre- 
sented in  tliis  pilot oprapli.  Tlie  camera  standn  on  I  lie  siiniinil  of  a  minor  divide  in  tlie 
zone  of  nivation. 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         205 

These  features  are  surprising  because  neither  Whymper  ^  nor 
Wolf  ^  mentions  the  former  greater  extent  of  the  ice  on  the  vol- 
canoes of  Ecuador,  only  ten  or  twelve  degrees  farther  north. 
Moreover,  Reiss  ^  denies  that  the  hypothesis  of  universal  climatic 
change  is  supported  by  the  facts  of  a  limited  glaciation  in  the 
High  Andes  of  Ecuador ;  and  J.  W.  Gregory  *  completely  overlooks 
published  proof  of  the  existence  of  former  more  extensive  glaciers 
elsewhere  in  the  Andes : 

"...  the  absence  not  only  c^  any  traces  of  former  more  ex- 
tensive glaciation  from  the  tropic^,  as  in  the  Andes  and  Kiliman- 
djaro,  but  also  from  the  Cape."  |He  says  further:  "In  spite  of 
the  extensive  glaciers  now  in  existence  on  the  higher  peaks  of  the 
Andes,  there  is  practically  no  evidjence  of  their  former  greater 
extension."  ( !)  t\ 

AVhymper  spent  most  of  his  time'  in  exploring  recent  volcanoes 
or  those  recently  in  eruption,  hence  did  not  have  the  most  favora- 
ble opportunities  for  gathering  significant  data.  Reiss  was  car- 
ried off  his  feet  by  the  attractiveness  of  the  hypothesis  ^  relating 
to  the  effect  of  glacial  denudation  on  the  elevation  of  the  snowline. 
Gregory  appeared  not  to  have  recognized  the  work  of  Hettner  on 
the  Cordillera  of  Bogota  and  of  Sievers  "  and  Acosta  on  the  Sierra 
Nevada  de  Santa  Marta  in  northern  Colombia. 

The  importance  of  the  glacial  features  of  the  Cordillera  Vilca- 
pampa  developed  on  a  great  scale  in  very  low  latitudes  in  the 
southern  hemisphere  is  twofold :  first,  it  bears  on  the  still  unset- 
tled problem  of  the  universality  of  a  colder  climate  in  the  Pleis- 
tocene, and,  second,  it  supplies  additional  data  on  the  relative  de- 
pression of  the  snowline  in  glacial  times  in  the  tropics.     Snow- 


*  Travels  Amongst  the  Great  Andes  of  the  Equator,  1892. 
^  Geografia  y  Geologia  del  Ecuador,  1892. 

'  Das  Hochgebirge  der  Republik  Ecuador,  Vol.  2,  2  Ost-Cordillera,  1902,  p.  162. 

*  Contributions  to  the  Geology  of  British  East  Africa;  Pt.  1,  The  Glacial  Geology 
of  Mount  Kenia,  Quart.  Journ.  Geol.  Soc,  Vol.  50,  1894,  p.  523. 

°  See  especially  A.  Penck  (Penck  and  Briickner),  Die  Alpen  im  Eiszeitalter,  1909, 
Vol.  1,  p.  6,  and  I.  C.  Russell,  Glaciers  of  Mount  Rainier,  18th  Ann.  Rcp't,  U.  S.  Geol. 
Surv.,  1896-97,  Sect.  2,  pp.  384-385. 

*  Die  Sierra  Nevada  de  Santa  Marta  und  die  Sierra  de  PerijS,  Zeitschrift  der 
Gesellschaft  fur  Erdkunde  zu  Berlin,  Vol.  23,  1888,  pp.  1-158. 


206  THE  ANDES  OF  SOUTHERN  PERU 

clad  mountains  near  the  equator  are  really  quite  rare.  Mount 
Kenia  rising  from  a  great  jungle  on  the  equator,  Kilimandjaro 
M-ith  its  two  peaks,  Kibo  and  Mawenzi,  two  hundred  miles  farther 
south,  and  Ingomwimbi  in  the  Ruwenzori  group  thirty  miles  north 
of  the  equator,  are  the  chief  African  examples.  A  few  mountains 
from  the  East  Indies,  such  as  Kinibalu  in  Borneo,  latitude  6°  north, 
have  been  found  glaciated,  though  now  without  a  snow  cover.  In 
.higher  latitudes  evidences  of  an  earlier  extensive  glaciation  have 
been  gathered  chiefly  from  South  America,  whose  extension  13° 
north  and  56°  south  of  the  equator,  combined  with  the  great  height 
of  its  dominating  Cordillera,  give  it  unrivaled  distinction  in  the 
study  of  mountain  glaciation  in  the  tropics. 

Furthermore,  mountain  summits  in  tropical  lands  are  delicate 
climatic  registers.  In  this  respect  they  compare  favorably  with 
the  inclosed  basins  of  arid  regions,  where  changes  in  climate  are 
clearly  recorded  in  shoreline  phenomena  of  a  familiar  kind.  Lofty 
mountains  in  the  tropics  are  iii  a  sense  inverted  basins,  the  lower 
snowline  of  the  past  is  like  the  higher  shoreline  of  an  interior 
basin ;  the  terminal  moraines  and  the  alluvial  fans  in  front  of  them 
are  like  the  alluvial  fans  above  the  highest  strandline ;  the  present 
snow  cover  is  restricted  to  mountain  summits  of  small  areal  ex- 
tent, just  as  the  present  water  bodies  are  restricted  to  the  lowest 
portions  of  the  interior  basin ;  and  successive  retreatal  stages  are 
marked  by  terminal  moraines  in  the  one  case  as  they  are  marked 
in  the  other  by  flights  of  terraces  and  beach  ridges. 

I  made  only  a  rapid  reconnaissance  across  the  Cordillera  Vilca- 
pampa  in  the  winter  season,  and  cannot  pretend  from  my  limited 
observations  to  solve  many  of  the  problems  of  the  field.  The  data 
are  incorporated  chiefly  in  the  chapter  on  Glacial  Features. 
In  this  place  it  is  proposed  to  describe  only  the  more  prominent 
glacial  features,  leaving  to  later  expeditions  the  detailed  descrip- 
tions upon  which  the  soliilioii  of  some  of  the  larger  problems  must 
depend. 

j  At  Chorpu'tira  three  prominent  stages  in  IIk;  retreat  of  the  ice 
are  recorded.  The  lowermost  stage  is  represented  by  the  great  fill 
of  morainic  and  outwash  material  at  the  junction  of  the  Choque- 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         207 


Scale  of  Miles 


PANTA  MT.  Q-  I8BZ3 


17618 


fc^ 


lira,  and  an  unnamed  valley  farther  south  at  an  elevation  of 
11,500  feet  (3,500  m.).  A  mile  below  Choquetira  a  second  moraine 
appears,  elevation  12,000  feet  (3,658  m.),  and  immediately  above 
the  village  a  third  at  12,800  (3,900  m.).  The  lowermost  moraine 
is  well  dissected,  the  second  is  ravined  and  broken  but  topo- 
graphically distinct,  the  third  is  sharp-crested  and  regular.  A 
fourth  though  minor  stage  is  represented  by  the  moraine  at  the 
snout  of  the  living  glacier 
and  still  less  important 
phases  are  represented  in 
some  valleys — possibly  the 
record  of  post-glacial 
changes  of  climate.  Each 
main  moraine  is  marked  by 
an  important  amount  of 
outwash,  the  first  and  third 
moraines  being  associated 
with  the  greatest  masses. 
The  material  in  the  moraines 
represents  only  a  part  of 
that  removed  to  form  the 
successive  steps  in  the  valley 
profile.  The  lowermost  one 
has  an  enormous  volume, 
since   it   is   the   oldest   and 


#^  i/e 


y;^ 


(  hoqu'  1< 


Mi' 


^  15189  '"  m'-»-  /,ri 


16178"  vQ> 


Fig.  136 — Glacial  sculpture  on  the  south- 
western flank  of  the  Cordillera  Vilcapampa. 
Flat-floored  valleys  and  looped  terminal  mo- 
raines below  and  glacial  steps  and  hanging 
valleys  are  characteristic.  The  present  snow- 
fields  and  glaciers  are  shown  by  dotted  contours. 


was  built  at  a  time  when  the  valley  was  full  of  waste.  It  is  fronted 
by  a  deep  fill,  over  the  dissected  edge  of  which  one  may  descend 
800  feet  in  half  an  hour.  It  is  chiefly  alluvial  in  character,  whereas 
the  next  higher  one  is  composed  chiefly  of  bowlders  and  is  fronted 
by  a  pronounced  bowlder  train,  which  includes  a  remarkable 
perched  bowlder  of  huge  size.  Once  the  valley  became  cleaned 
out  the  ice  would  derive  its  material  chiefly  by  the  slower 
process  of  plucking  and  abrasion,  hence  would  build  much  smaller 
moraines  during  later  recessional  stages,  even  though  the  stages 
were  of  equivalent  length. 

There  is  a  marked  difference  in  the  degree  of  dissection  of  the 


208  THE  ANDES  OF  SOUTHERN  PERU 

moraines.  The  lowermost  and  oldest  is  so  thoroughly  dissected 
as  to  exhibit  but  little  of  its  original  surface.  The  second  has 
been  greatly  modified,  but  still  possesses  a  ridge-like  quality  and 
marks  the  beginning  of  a  noteworthy  flattening  of  the  valley 
gradient.  The  third  is  as  sharp-crested  as  a  roof,  and  yet  was 
built  so  long  ago  that  the  flat  valley  floor  behind  it  has  been  modi- 
fied by  the  meandering  stream.  From  this  point  the  glacier  re- 
treated up-valley  several  miles  (estimated)  mthout  leaving  more 
than  the  thinnest  veneer  on  the  valley  floor.  The  retreat  must, 
therefore,  have  been  rapid  and  without  even  temporary  halts  until 
the  glacier  reached  a  position  near  that  occupied  today.  Both  the 
present  ice  tongues  and  snowfields  and  those  of  a  past  age  are 
emphasized  by  the  presence  of  a  patch  of  scrub  and  woodland  that 
extends  on  the  north  side  of  the  valley  from  near  the  snowline 
do^^^l  over  the  glacial  forms  to  the  lower  valley  levels. 

The  retreatal  stages  sketched  above  would  call  for  no  special 
comment  if  they  were  encountered  in  mountains  in  northern  lati- 
tudes. They  would  be  recognized  at  once  as  evidence  of  successive 
periodic  retreats  of  the  ice,  due  to  successive  changes  in  tempera- 
ture. To  understand  their  importance  when  encountered  in  very 
low  latitudes  it  is  necessary  to  turn  aside  for  a  moment  and  con- 
sider two  rival  hypotheses  of  glacial  retreat.  First  we  have  the 
hypothesis  of  periodic  retreat,  so  generally  applied  to  terminal 
moraines  and  associated  outwash  in  glaciated  mountain  valleys. 
This  implies  also  an  advance  of  the  ice  from  a  higher  position, 
the  whole  taking  place  as  a  result  of  a  climatic  change  from 
warmer  to  colder  and  back  again  to  warmer. 

But  evidences  of  more  extensive  mountain  glaciation  in  the 
past  do  not  in  themselves  prove  a  change  in  climate  over  the  whole 
earth,  i  ii  an  epoch  of  fixed  climate  a  glacier  system  may  so  deeply 
and  thoroughly  erode  a  mountain  mass,  lliat  the  former  glaciers 
may  eitli<r  diminish  in  size  or  disappear  altogether.  As  the  work 
of  excavation  proceeds,  the  catchment  basins  are  sunk  to,  and  at 
last  below,  the  snowline;  ])road  tributary  spurs  whose  snows 
nourish  the  glaciers,  may  l)e  reduced  to  narrow  or  skeleton  ridges 
with  little  snow  to  contribute  to  tlic  valleys  on  either  hand;  tlie 


m 

k 

^^..^.      ^.^-  ^^_^^^ 

\ 

m 

i 

1 

»w^:.:i*?l* 

b 

Fig.  137. 


■s^i.       ■^,*:- 


■■*^;^. 


.•^**ii>' 


Fig.  138. 


Fig.  137 — Looking  up  a  spurless  flat-floored  glacial  trough  near  the  Cliucuito  pass 
in  the  Cordillera  Vilcapampa  from  14,200  feet  (4,330  m.).  Note  the  looped  terminal 
and.  lateral  moraines  on  the  steep  valley  wall  on  the  left.  A  stone  fence  from  wall  to 
wall  serves  to  inclose  the  flock  of  the  mountain  shepherd. 

Fig.  138 — Terminal  moraine  in  the  glaciated  Choquetira  Valley  below  Choquetira. 
The  people  who  live  here  have  an  abundance  of  stones  for  building  corrals  and  stone 
houses.  The  upper  edge  of  the  timber  belt  (cold  timber  line)  is  visible  beyond  the 
houses.     Elevation  12,100  feet   (3,090  m.). 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         209 

glaciers  retreat  and  at  last  disappear.  There  would  be  evidences 
of  glaciation  all  about  the  ruins  of  the  former  loftier  mountain, 
but  there  would  be  no  living  glaciers.  And  yet  the  climate  might 
remain  the  same  throughout. 

It  is  this  "topographic"  hypothesis  that  Reiss  and  Stiibel 
accept  for  the  Ecuadorean  volcanoes.  Moreover,  the  volcanoes  of 
Ecuador  are  practically  on  the  equator — a  very  critical  situation 
when  we  wish  to  use  the  facts  they  exhibit  in  the  solution  of  such 
large  problems  as  the  contemporaneous  glaciation  of  the  two 
hemispheres,  or  the  periodic  advance  and  retreat  of  the  ice  over 
the  whole  earth.  This  is  not  the  place  to  scrutinize  either  their 
facts  or  their  hypothesis,  but  I  am  under  obligations  to  state  very 
emphatically  that  the  glacial  features  of  the  Cordillera  Vilca- 
pampa  require  the  climatic  and  not  the  topographic  hypothesis. 
Let  us  see  why. 

The  differences  in  degree  of  dissection  and  the  flattening 
gradient  up-valley  that  we  noted  in  a  preceding  paragraph  leave 
no  doubt  that  each  moraine  of  the  bordering  valleys  in  the  Vilca- 
pampa  region,  represents  a  prolonged  period  of  stability  in  the 
conditions  of  topography  as  well  as  of  temperature  and  precipita- 
tion. If  change  in  topographic  conditions  is  invoked  to  explain 
retreat  from  one  position  to  the  other  there  is  left  no  explanation 
of  the  periodicity  of  retreat  which  has  just  been  established.  If 
a  period  of  cold  is  inaugurated  and  glaciers  advance  to  an  ulti- 
mate position,  they  can  retreat  only  through  change  of  climate 
effected  either  by  general  causes  or  by  topographic  development  , 
to  the  point  where  the  snowfields  become  restricted  in  size.  In 
the  case  of  climatic  change  the  ice  changes  are  periodic.  In  the 
case  of  retreat  due  to  topographic  change  there  should  be  a  steady 
or  non-periodic  falling  back  of  the  ice  front  as  the  catchment 
basins  decrease  in  elevation  and  the  snow-gathering  ridges  tribu- 
tary to  them  are  reduced  in  height. 

Further,  the  matterhorns  of  the  Cordillera  Vilcapampa  are  not 
bare  but  snow-covered,  vigorous  glaciers  several  miles  in  length 
and  large  sno^vfields  still  survive  and  the  divides  are  not  aretes  \ 
but  broad  ridges.    In  addition,  the  last  two  moraines,  composed 


210 


THE  ANDES  OF  SOUTHERN  PERU 


^^^^3Th7?^5^5^ 


of  very  loose  m^lAal,  are  well  preserved.  They  indicate  clearly 
that  the  time  since^Mpir  fonnation  has  witnessed  no  wholesale 
topographic  change.  tI  (1)  no  important  topographic  changes 
|have  taken  place,  and  (2)  a  vigorous  glacier  lay  for  a  long  period 
back  of  a  given  moraine,  and  (3)  suddenly  retreated  several 
imiles  and  again  became  stable,  we  are  left  without  confidence 
in  the  application  of  the  topographic  hypothesis  to  the  glacial 

features  of  the  Vilcapampa 
region.  Glacial  retreat  may 
be  suddenly  begun  in  the 
case  of  a  late  stage  of  topo- 
graphic development,  but  it 
should  be  an  orderly  retreat 
marked  by  a  large  number 
of  small  moraines,  or  at 
least  a  plentiful  strewing  of 
the  valley  floor  with  debris. 

The  number  of  moraines 
in  the  various  glaciated  val- 
leys of  the  Cordillera  Vil- 
capampa differ,  omng  to 
differences  in  elevation  and 
to  the  variable  size  of  the 
catchment  basins.  All  val- 
leys, however,  display  the 
same  sudden  change  from  moraine  to  moraine  and  the  same 
characteristics  of  gradient.  In  all  of  them  the  lowermost 
moraine  is  always  more  deeply  eroded  than  the  higher 
moraines,  in  all  of  them  glacial  erosion  was  suflRciently  pro- 
longed greatly  to  modify  llic  valley  walls,  scour  out  lake  basins, 
oi-  broad  fla(  valley  flooi's,  develop  cirques,  aretes,  and  pinnacled 
ridges  in  limited  number.  In  some,  glaciation  was  carried  to  the 
point  where  only  skeleton  divides  remained,  in  most  places  broad 
massive  ridges  or  mountain  knots  persist.  In  spite  of  all  these 
differences  successive  moraines  were  formed,  separated  by  long 
stretches  eitliei-  tl)inl\-  coxcred  wilh  lill  or  e\))osing  bare  rock. 


^16300  ,, 

Mt.Pumasillo 

Scale  of  Miles 

0 1 


Fio.   139 — Glacial   features  on  the  eastern 
slopes  of  the  Cordillera  Vilcapampa. 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         211 

In  examining  this  group  of  features  it  i|ji^portant  to  rec- 
ogTiize  the  essential  fact  that  though  th|^umber  of  moraines 
varies  from  valley  to  valley,  the  diff eren^pf  in  character  between 
the  moraines  at  low  and  at  high  elevations  in  a  single  valley  are 
constant.  It  is  also  clear  that  everywhere  the  ice  retreated  and 
advanced  periodically,  no  matter  with  what  topographic  features 
it  was  associated,  whether  those  of  maturity  or  of  youth  in  the 
glacial  cycle.  We,  therefore,  conclude  that  topographic  changes 
had  no  significant  part  to  pl^y  in  the  glacial  variations  in  the 
Cordillera  Vilcapampa.  ' 

The  country  west  of  the  Cordillera  Vilcapampa  had  been  re- 
duced to  early  topographic  maturity  before  the  Ice  Age,  and  then 
uplifted  with  only  moderate  erosion  of  the  masses  of  the  inter- 
fluves.    That  on  the  east  had  passed  through  the  same  sequence  \ 
of  events,  but  erosion  had  been  carried  much  farther.    The  reason   \ 
for  this  is  found  in  a  strong  climatic  contrast.     The  eastern  is     ) 
the  windward  aspect  and  receives  much  more  rain  than  the  west-  / 
em.    Therefore,  it  has  more  streams  and  more  rapid  dissection. 
The  result  was  that  the  eastern  slopes  were  cut  to  pieces  rapidly 
after  the  last  great  regional  uplift ;  the  broad  interfluves  were  nar- 
rowed to  ridges.     The  region  eastward  from  the  crest  of  the 
Cordillera  to  the  Pongo  de  Mainique  looks  very  much  like  the 
western  half  of  the  Cascade  Mountains  in  Oregon — the  summit 
tracts  of  moderate  declivity  are  almost  all  consumed. 

The  effect  of  these  climatic  and  topographic  contrasts  is  mani- 
fested in  strong  contrasts  in  the  position  and  character  of  the  gla- 
cial forms  on  the  opposite  slopes  of  the  range.  At  Pampaconas 
on  the  east  the  lowermost  terminal  moraine  is  at  least  a  thousand 
feet  below  timber  line.  Between  Vilcabamba  pueblo  and  Puquiura 
the  terminal  moraine  lies  at  11,200  feet  (3,414  m.).  By  contrast 
the  largest  Pleistocene  glacier  on  the  western  slope,  nearly  twelve 
miles  long,  and  the  largest  along  the  traverse,  ended  several  miles 
below  Choquetira  at  11,500  feet  (3,504  m.)  elevation,  or  just  at  the 
timber  line.  Thus,  the  steeper  descents  of  the  eastern  side  of  the 
range  appear  to  have  carried  short  glaciers  to  levels  far  lower 
than  those  attained  by  the  glaciers  of  the  w^estern  slope. 


212 


THE  ANDES  OF  SOUTHERN  PERU 


I'    t' 

^S    I67S4  O 


It  seems  at  first  strange  that  the  largest  glaciers  were  west 
of  the  divide  between  the  Urubamba  and  the  Apurimac,  that  is,  on 
the  relatively  dry  side  of  the  range.    The  reason  lies  in  a  strik- 
ing   combination    of    topo- 
graphic and  climatic  condi 
tions.      Snow    is    a    mobile 
form  of  precipitation  that  is 
shifted   about  by  the  wind 
like    a    sand    dune    in    the 
desert.     It  is  not  required, 
like  water,  to  begin  a  down- 
hill movement  as  soon  as  it 
strikes  the  earth.     Thus,  it 
is    a   noteworthy   fact   that 
snow    drifting    across    the 
divides  may  ultimately  cause 
the  largest  snowfields  to  lie 
where    the    least    snow    ac- 
tually falls.     This   is  illus- 
trated  in   the   Bighorns    of 
Wyoming  and  others  of  our 
western  ranges.    It  is,  how- 
ever, not  the  wet  snow  near 
the  snowline,  but  chiefly  the 
dry  snow  of  higher  altitudes 
that   is   affected.     What   is 
now  the  dry  or  leeward  side 


';i«iii'ifa. 


Fig.  140 — Glacial  sculpture  in  the  heart 
of  the  Cordillera  Vilc:ipami)a.  In  places  the 
topography  lias  so  high  a  relief  that  the  glaciers 
eeem  almost  to  overhang  the  valleys.  See  Figs. 
90  and   179   for  photograplis. 


of  the  Cordillera  appears  in  glacial  times  to  have  actually  re- 
ceived more  snow  than  the  wet  Avindward  side. 

The  topography  conspired  to  increase  this  contrast.  In  place 
of  many  streams,  direct  descents,  a  dispersion  of  snow  in  many 
valleys,  as  on  Hh?  cast,  the  western  slopes  had  indirect  descents, 
gentler  vall«'y  profiles,  and  that  higher  degree  of  concentration  of 
drainage  which  naturally  goes  with  topographic  maturity.  For 
example,  there  is  nothing  in  the  east  to  compare  with  the  big  spur- 
less  valley  near  tlic  pass  above  Arin.i.     The  side  walls  were  so 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         213 

extensively  trimmed  that  the  valley  was  turned  into  a  trough. 
The  floor  was  smoothed  and  deepened  and  all  the  tributary  gla- 
ciers were  either  left  high  up  on  the  bordering  slopes  or  entered 
the  main  valley  with  very  steep  profiles ;  their  lateral  and  terminal 
moraines  now  hang  in  festoons  on  the  steep  side  walls.  Moreover, 
the  range  crest  is  trimmed  from  the  west  so  that  the  serrate  sky- 
line is  a  feature  rarely  seen  from  eastern  viewpoints.  This  may 
not  hold  true  for  more  than  a  small  part  of  the  Cordillera.  It  was 
probably  emphasized  here  less  by  the  contrasts  already  noted 
than  by  the  geologic  structure.  The  eastward-flowing  glaciers 
descended  over  dip  slopes  on  highly  inclined  sandstones,  as  at 
Pampaconas.  Those  flowing  westward  worked  either  in  a  jointed 
granite  or  on  the  outcropping  edges  of  the  sandstones,  where  the 
quarrying  process  known  as  glacial  plucking  permitted  the  devel- 
opment of  excessively  steep  slopes. 

There  are  few  glacial  steps  in  the  eastern  valleys.  The  west- 
tern  valleys  have  a  marvelous  display  of  this  striking  glacial  fea- 
ture. The  accompanying  hachure  maps  show  them  so  well  that 
little  description  is  needed.  They  are  from  50  to  200  feet  high. 
Each  one  has  a  lake  at  its  foot  into  which  the  divided  stream 
trickles  over  charming  waterfalls.  All  of  them  are  clearly  asso- 
ciated with  a  change  in  the  volume  of  the  glacier  that  carved  the 
valley.  Wherever  a  tributary  glacier  entered,  or  the  side  slopes 
increased  notably  in  area,  a  step  was  formed.  By  retreat  some 
of  them  became  divided,  for  the  process  once  begun  would  push 
the  step  far  up  valley  after  the  manner  of  an  extinguishing  water- 
fall. 

The  retreat  of  the  steps,  the  abrasion  of  the  rock,  and  the  sap- 
ping of  the  cirques  at  the  valley  heads  excavated  the  upper  val- 
leys so  deeply  that  they  are  nearly  all,  as  W.  D.  Johnson  has  put 
it,  ''down  at  the  heel."  Thus,  above  Arma,  one  plunges  suddenly 
from  the  smooth,  grassy  glades  of  the  strongly  glaciated  valley 
head  down  over  the  outer  slopes  of  the  lowermost  terminal 
moraine  to  the  steep  lower  valley.  Above  the  moraine  are  fine 
pastures,  in  the  steep  valley  below  are  thickets  and  rocky  defiles. 
There  are  long  quiet  reaches  in  the  streams  of  the  glaciated  valley 


214  THE  ANDES  OF  SOUTHERN  PERU 

heads  besides  pretty  lakes  and  marshes.  Below,  the  stream  is 
s\Yift,  almost  torrential.  Arma  itself  is  built  upon  alluvial  de- 
posits of  glacial  origin.  A  mile  farther  down  the  valley  is  con- 
stricted and  steep-walled — really  a  canyon. 

Though  the  glaciers  have  retreated  to  the  summit  region,  they 
are  by  no  means  nearing  extinction.  The  clear  blue  ice  of  the 
glacier  descending  from  Mt.  Soiroccocha  in  the  Arma  A^alley 
seems  almost  to  hang  over  the  precipitous  valley  border.  In 
curious  contrast  to  its  suggestion  of  cold  and  storm  is  the  patch 
of  dark  green  woodland  which  extends  right  up  to  its  border.  An 
earthquake  might  easily  cause  the  glacier  to  invade  the  woodland. 
Some  of  the  glaciers  between  Choquetira  and  Arma  rest  on 
terminal  moraines  whose  distal  faces  are  from  200  to  300  feet 
high.  The  ice  descending  southea:sterly  from  Panta  Mt.  is  a  good 
illustration.  Earlier  positions  of  the  ice  front  are  marked  by 
equally  large  moraines.  The  one  nearest  that  engaged  by  the  liv- 
ing glacier  confines  a  large  lake  that  discharges  through  a  gap  in 
the  moraine  and  over  a  waterfall  to  the  marshy  floor  of  the  valley. 

Retreat  has  gone  so  far,  however,  that  there  are  only  a  few 
large  glacier  systems.  Most  of  the  tributaries  have  withdrawn 
toward  their  snowfields.  In  place  of  the  twenty  distinct  glaciers 
now  lying  between  the  pass  and  the  terminal  moraine  below  Cho- 
quetira, there  was  in  glacial  times  one  great  glacier  with  twenty 
minor  tributaries.  The  cirques  now  partly  filled  with  damp  snow 
must  then  have  been  overflowing  with  dry  snow  above  and  ice  be- 
low. Some  of  the  glaciers  were  over  a  thousand  feet  thick;  a  few 
were  nearly  two  thousand  feet  thick,  and  the  cirques  that  fed 
them  held  snow  and  ice  at  least  a  half  mile  deep.  Such  a  remark- 
ably complete  set  of  glacial  features  only  700  miles  from  the 
equator  is  striking  evidence  of  the  moist  climate  on  the  windward 
eastern  part  of  the  great  Andean  Cordillera,  of  tlio  universal 
change  in  climate  in  the  glacial  period,  and  of  the  powerful  domi- 
nating effects  of  ice  erosion  in  this  region  of  unsurpnssod  Alpine 
relief. 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         215 

THE  VILCAPAMPA   BATHOLITII   AND  ITS  TOPOGRAPHIC   EFFECTS 

The  main  axis  of  the  Cordillera  Vilcapampa  consists  of  granite] 
in  the  form  of  a  batholith  between  crystalline  schists  on  the  one/ 
hand  (southwest),  and  Carboniferous  limestones  and  sandstoneg 
and  Silurian  shales  and  slates  on  the  other  (northeast).  It  is  noi 
a  domal  uplift  in  the  region  in  which  it  was  observed  in  1911,  bur 


PAMPACONAS      - 
-'VVALLEy 

CORDILLERA     VILCAPAMPA 

-■ —      — ~--^^--^""        -j^^^                   ^^^ 

Mky  E." 

__SAI\I  DSTONE 

!^^^3^                               GRANITE 

;;;;;;^^^;:;;^/  p  0  R  p  H  y  R  Y 

— "Z^ '       ■ 

Fig.  141 — Composite  geologic  section  on  the  northeastern  border  of  tlic  Cordillera 
Vilcapampa,  in  the  vicinity  of  Panipaconas,  to  show  the  deformative  effects  of  the 
granite  intrusion.  There  is  a  limited  amount  of  limestone  near  the  border  of  the 
Cordillera.  Both  limestone  and  sandstone  axe  Carboniferous.  See  Appendix  B.  See 
also  Figs.  142  and  146.     The  section  is  about  15  miles  long. 


an  axial  intrusion,  in  places  restricted  to  a  narrow  belt  not  more 
than  a  score  of  miles  across.  As  w^e  should  expect  from  the 
variable  nature  of  the  invaded  material,  the  granite  belt  is  not 
uniform  in  width  nor  in  the  character  of  its  marginal  features. 
In  places  the  intrusion  has  produced  strikingly  little  alteration 
of  the  country  rock;  in  other  localities  the  granite  has  been 
injected  into  the  original  material  in  so  intimate  a  manner  as 
almost  completely  to  alter  it,  and  to  give  rise  to  a  very  broad 
zone  of  highly  metamorphosed  rock.  Furthermore,  branches  were 
developed  so  that  here  and  there  tributary  belts  of  granite 
extend  from  the  main  mass  to  a  distance  of  many  miles.  Out- 
lying batholiths  occur  whose  common  petrographic  character  and 
similar  manner  of  occurrence  leave  little  doubt  that  they  are 
related  abyssally  to  a  common  plutonic  mass. 

The  Vilcapampa  batholith  has  two  highly  contrasted  borders, 
whether  we  consider  the  degree  of  metamorphism  of  the  country 
rock,  the  definition  of  the  border,  or  the  resulting  topographic 
forms.  On  the  northeastern  ridge  at  Colpani  the  contact  is  so 
sharp  that  the  outstretched  arms  in  some  places  embrace  tj^pical 


21G 


THE  ANDES  OF  SOUTHERN  PERU 


granite  on  the  one  hand  and  almost  unaltered  shales  and  slates  on 
the  other.  Inclusions  or  xenoliths  of  shale  are  common,  however, 
ten  and  fifteen  miles  distant,  though  they  are  prominent  features 
in  a  belt  only  a  few  miles  wide.  The  lack  of  more  intense  contact 
effects  is  a  little  remarkable  in  view  of  the  altered  character  of 
EASTERN  BORDER  RANGES  ^he  iuclusious,  all  of  whlch  are 
crystalline  in  contrast  to  the  fis- 
sile shales  from  which  they  are 
Fig.  142— The  deformative  effects  of    chiefly  derived.    Inclusions  with- 


in a  few  inches  of  the  border 
fall  into  a  separate  class,  since 
they  show  in  general  but  trifling 
alteration    and    preserve    their 


the  Vilcapampa  intrusion  on  the  north- 
eastern border  of  the  Cordillera.  The 
deformed  strata  are  heav^y-bedded  sand- 
stones and  shales  and  the  igneous  rocks 
are  chiefly  granites  with  bordering  porphy- 
ries. Looking  northwest  near  Puquiura. 
For  conditions  near  Pampaconas,  looking  original  cleavagC  plaues.  It  ap- 
in  the  opposite  direction,  see  Fig.  141.    For  ox 

conditions  on  the  other  side  of  the  Cordil-      pcarS   that  the   depth   of   the   iu- 

lera  see  Fig.  146.  trusiou   must   have   been   rela- 

tively slight  or  the  intrusion  sudden,  or  both  shallow  and  sudden, 
conditions  which  produce  a  narrow  zone  of  metamorphosed  ma- 
terial and  a  sharp  contact. 

The  relation  between  shale  and  granite  at  Colpani  is  shown 
in  Fig.  143.  Projections  of  granite  extend  several  feet  into  the 
shale  and  slate  and  generally 
end  in  blunt  barbs  or  knobs. 
In  a  few  places  there  is  an  in- 
timate mixture  of  irregular 
slivers  and  blocks  of  crystal- 
lized sediments  in  a  granitic 
groundmass,  with  sharp  lines 
of  demarcation  between  igneous 
and  included  material.  The 
contact  is  vortical  for  at  least 
several    miles.      It    is   probable 


Fkj.  ]4;{ — llrlatioii  of  granite  intru- 
sion to  schist  on  the  northeastern  border 
of  the  Vilcapampa  batliolith  near  tlie 
bridge  of  Colpani,  lower  end  of  tlic  granite 
Canyon  of  Toronfoy.  Tlif  sections  are 
from  15  to  25  feet  high  and  represent  con- 
ditions at  different  levels  along  the  well- 
defined  contact. 


that  other  localities  on  the  con- 
tact (exhibit  much  greater  modification  and  insasioji  ol'  the  weak 
slialoH  and  slales,  but  at  Colpani  the  plienomcna  ai'e  both  simple 
;iiid  restricted  in  development. 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         217 

The  highly  mineralized  character  of  the  bordering  sedimentary 
strata,  and  the  presence  of  numbers  of  complementary  dikes, 
nearly  identical  in  character  to  those  in  the  parent  granite  now 
exposed  by  erosion  over  a  broad  belt  roughly  parallel  to  the  con- 
tact, supplies  a  basis  for  the  inference  that  the  granite  may  under- 
lie the  former  at  a  slight  depth,  or  may  have  had  far  greater  meta- 
morphic  effects  upon  its  sedimentary  roof  than  the  intruded 
granite  has  had  upon  its  sedimentary  rim. 

The  physiographic  features  of  the  contact  belt  are  of  special 
interest.  No  available  physiographic  interpretation  of  the  topog- 
raphy of  a  batholith  includes  a  discussion  of  those  topographic 
and  drainage  features  that  are  related  to  the  lithologic  character 
of  the  intruded  rock,  the  manner  of  its  intrusion,  or  the  depth  of 
erosion  since  intrusion.  Yet  each  one  of  these  factors  has  a  dis- 
tinct topographic  effect.  We  shall,  therefore,  turn  aside  for  a 
moment  from  the  detailed  discussion  of  the  Vilcapampa  region 
to  an  examination  of  several  physiographic  principles  and  then 
return  to  the  main  theme  for  applications. 

It  is  recognized  that  igneous  intrusions  are  of  many  varieties 
and  that  even  batholithic  invasions  may  take  place  in  rather 
widely  different  ways.  Highly  heated  magmas  deeply  buried  be- 
neath the  earth's  surface  produce  maximum  contact  effects,  those 
nearer  the  surface  may  force  the  strata  apart  without  extreme 
lithologic  alterations  of  the  displaced  beds,  while  through  the 
stoping  process  a  sedimentary  cover  may  be  largely  absorbed  and 
the  magmas  may  even  break  forth  at  the  surface  as  in  ordinary 
vulcanism.  If  the  sedimentary  beds  have  great  vertical  variation 
in  resistance,  in  attitude,  and  in  composition,  there  may  be  af- 
forded an  opportunity  for  the  display  of  quite  different  effects 
at  different  levels  along  a  given  contact,  so  that  a  great  variety 
of  physical  conditions  will  be  passed  by  the  descending  levels  of 
erosion.  At  one  place  erosion  may  have  exposed  only  the  summit 
of  the  batholith,  at  another  the  associated  dikes  and  sheets  and 
ramifying  branches  may  be  exposed  as  in  the  zone  of  fracture,  at 
a  third  point  the  original  zone  of  flowage  may  be  reached  with 
characteristic  marginal  schistosity,  while  at  still  greater  depths 


218  THE  ANDES  OF  SOUTHERN  PERU 

there  may  be  uncovered  a  highly  metamorphosed  rim  of  resistant 
sedimentary  rock. 

The  mere  enumeration  of  these  variable  structural  features  is 
sufficient  to  show  how  variable  we  should  expect  the  associated 
land  forms  to  be.  Were  the  forms  of  small  extent,  or  had  they 
but  slight  distinction  upon  comparison  with  other  erosional  ef- 
fects, they  would  be  of  little  concern.  They  are,  on  the  contrary, 
very  extensively  developed;  they  affect  large  numbers  of  lofty 
mountain  ranges  besides  still  larger  areas  of  old  land  masses  sub- 
jected to  extensive  and  deep  erosion,  thus  laying  bare  many  batho- 
liths  long  concealed  by  a  thick  sedimentary  roof. 

The  differences  between  intruded  and  country  rock  dependent 
upon  these  diversified  conditions  of  occurrence  are  increased  or 
diminished  according  to  the  history  of  the  region  after  batholithic 
invasion  takes  place.  Regional  metamorphism  may  subsequently 
induce  new  structures  or  minimize  the  effects  of  the  old.  Joint 
systems  may  be  developed,  the  planes  widely  spaced  in  one  group 
of  rocks  giving  rise  to  monolithic  masses  very  resistant  to  the 
agents  of  weathering,  while  those  of  an  adjacent  group  may  be  so 
closely  spaced  as  greatly  to  hasten  the  rate  of  denudation.  There 
may  be  developed  so  great  a  degree  of  schistosity  in  one  rock  as 
to  give  rise  (with  vigorous  erosion)  to  a  serrate  topography;  on 
the  other  hand  the  forms  developed  on  the  rocks  of  a  batholith 
may  be  massive  and  coarse-textured. 

To  these  diversifying  conditions  may  be  added  many  others 
involving  a  large  part  of  the  field  of  dynamic  geology.  It  will 
perhaps  suffice  to  mention  two  others :  the  stage  of  erosion  and 
the  special  features  related  to  climate.  If  a  given  intrusion  has 
been  accompanied  by  an  important  amount  of  uplift  or  marginal 
compression,  vigorous  erosion  may  follow,  whereupon  a  chance 
will  be  offered  for  the  development  of  the  greatest  contrast  in  the 
degree  of  boldness  of  topographic  forms  developed  ii]ion  rocks  of 
unequal  resistance.  Ultimately  these  contrasts  will  diminish  in 
intensity,  as  in  the  cnsf  of  .'ill  i-o^'iojinl  differences  of  relief,  with 
progress  toward  the  end  of  the  normal  cycle  of  erosion.  If  pene- 
j)lnn?i1ion   onsno,   only  feeble  topographic  diffcrcnefs  may  mark 


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EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         219 

the  line  of  contact  which  was  once  a  prominent  topographic  fea- 
ture. With  reference  to  the  effects  of  climate  it  may  be  said  sim- 
ply that  a  granite  core  of  batholithic  origin  may  extend  above  the 
snowline  or  above  timber  line  or  into  the  timbered  belt,  whereas 
the  invaded  rock  may  occur  largely  below  these  levels  with  obvi- 
ous differences  in  both  the  rate  and  the  kind  of  erosion  affecting 
the  intruded  mass. 

If  we  apply  the  foregoing  considerations  to  the  Cordillera 
Vilcapampa,  we  shall  find  some  striking  illustrations  of  the  prin- 
ciples involved.  The  invasion  of  the  granite  was  accompanied  by 
moderate  absorption  of  the  displaced  rock,  and  more  especially 
by  the  marginal  pushing  aside  of  the  sedimentary  rim.  The  im- 
mediate effect  must  have  been  to  give  both  intruded  rock  and  coun- 
try rock  greater  height  and  marked  ruggedness.  There  followed 
a  period  of  regional  compression  and  torsion,  and  the  develop- 
ment of  widespread  joint  systems  with  strikingly  regular  features. 
In  the  Silurian  shales  and  slates  these  joints  are  closely  spaced; 
in  the  granites  they  are  in  many  places  twenty  to  thirty  feet, 
apart.  The  shales,  therefore,  offer  many  more  points  of  attack 
and  have  weathered  down  into  a  smooth-contoured  topography 
boldly  overlooked  along  the  contact  by  w^alls  and  peaks  of  granite 
In  some  cases  a  canyon  wall  a  mile  high  is  developed  entirely  on 
two  or  three  joint  planes  inclined  at  an  angle  no  greater  than  15° . 
The  effect  in  the  granite  is  to  give  a  marked  boldness  of  relief, 
nowhere  more  strikingly  exhibited  than  at  Huadquiiia,  below 
Colpani,  where  the  foot-hill  slopes  developed  on  shales  and  slates 
suddenly  become  moderate.  The  river  flows  from  a  steep  and  all 
but  uninliabited  canyon  into  a  broad  valley  whose  slopes  are  dot- 
ted with  the  terraced  chacras,  or  farms,  of  the  mountain  Indians. 

The  Torontoy  granite  is  also  homogeneous  while  the  shales 
and  slates  together  with  their  more  arenaceous  associates  occur 
in  alternating  belts,  a  diversity  which  increases  the  points  of  at- 
tack and  the  complexity  of  the  forms.  Tending  toward  the  same 
result  is  the  greater  hardness  of  the  granite.  The  tendency  of  the 
granite  to  develop  bold  forms  is  accelerated  in  lofty  valleys  dis- 
posed about  snow-clad  peaks,  where  glaciers  of  great  size  once 


V 


220  THE  ANDES  OF  SOUTHERN  PERU 

existed,  and  where  small  glaciers  still  linger.  The  plucking  action 
of  ice  has  an  excellent  chance  for  expression,  since  the  granite 
may  be  quarried  cleanly  without  the  production  of  a  large  amount 
of  spoil  which  would  load  the  ice  and  diminish  the  intensity  of  its 
plucking  action. 

As  a  whole  the  Central  Andes  passed  through  a  cycle  of  ero- 
sion in  late  Tertiary  time  which  was  interrupted  by  uplift  after 
the  general  surface  had  been  reduced  to  a  condition  of  topo- 
graphic maturity.  Upon  the  granites  mature  slopes  are  not  de- 
veloped except  under  special  conditions  (1)  of  elevation  as  in  the 
small  batholith  above  Chuquibambilla,  and  (2)  where  the  granite 
is  itself  bordered  by  resistant  schists  which  have  upheld  the  sur- 
face over  a  broad  transitional  belt.  Elsewhere  the  granite  is 
marked  by  exceedingly  rugged  forms :  deep  steep-walled  canyons, 
precipitous  cirques,  matterhorns,  and  bold  and  extended  escarp- 
ments of  erosion.  In  the  shale  belt  the  trails  run  from  valley  to 
valley  in  every  direction  without  special  difficulties,  but  in  the 
granite  they  follow  the  rivers  closely  or  cross  the  axis  of  the 
range  by  carefully  selected  routes  which  generally  reach  the  limit 
of  perpetual  snow.  Added  interest  attaches  to  these  bold  topo- 
graphic forms  because  of  the  ruins  now  found  along  the  canyon 
walls,  as  at  Torontoy,  or  high  up  on  the  summit  of  a  precipitous 
spur,  as  at  Machu  Picchu  near  the  bridge  of  San  Miguel. 

The  Vilcapampa  batholith  is  bordered  on  the  southwest  by  a 
series  of  ancient  schists  with  which  the  granite  sustains  quite  dif- 
ferent relations.  No  sharp  dividing  line  is  visible,  the  granite 
extending  along  the  planes  of  foliation  for  sucli  long  distances  as 
in  places  to  appear  almost  interbodded  with  the  scliists.  The  re- 
lation is  all  the  more  striking  in  view  of  the  trifling  intrusions 
effected  in  the  case  of  the  seemingly  much  weaker  shales  on  the 
opposite  contact.  Nor  is  llio  metamorphism  of  Die  invaded  rock 
limited  to  simple  intrusion.  For  several  miles  beyond  the  zone 
of  iiiff'Tisfr  crfools  the  schists  have  been  enriched  with  quartz  to 
sucli  an  extont  that  thoir  originnl  darker  color  has  been  changed 
to  light  gray  or  dull  white.  At  a  distance  they  may  even  appear 
as   homogeneous   and  light-colored   as   the   granite.     At  distant 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         221 

points  the  schists  assume  a  darker  hue  and  take  on  the  characters 
of  a  rather  typical  mica  schist. 

It  is  probable  that  the  Vilcapampa  intrusion  is  one  of  a  family 
of  batholiths  which  further  study  may  show  to  extend  over  a 
much  larger  territory.  The  trail  west  of  Abancay  was  followed 
quite  closely  and  accidentally  crosses  two  small  batholiths  of 
peculiar  interest.    Their  limits  were  not  closely  followed  out,  but 


Fig.  146 — Deformative  effects  on  limestone  strata  of  the  granite  intrusion  on  the 
southwestern  border  of  the  Vilcapampa  batholith  above  Chuquibambilla.  Fig.  147  is  on 
the  same  border  of  the  batholith  several  miles  farther  northwest.  The  granite  mass 
on  the  right  is  a  small  outlier  of  the  main  batholith  looking  south.  The  limestone 
is  Cretaceous.     See  Appendix  C  for  locations. 

were  accurately  determined  at  a  number  of  points  and  the  remain- 
ing portion  of  the  contact  inferred  from  the  topography.  In  the 
case  of  the  larger  area  there  may  indeed  be  a  connection  west- 
ward with  a  larger  mass  which  probably  constitutes  the  ranges 
distant  some  five  to  ten  miles  from  the  line  of  traverse. 

These  smaller  intrusions  are  remarkable  in  that  they  appear 
to  have  been  attended  by  little  alteration  of  either  invading  or 
invaded  rock,  though  the  granites  were  observed  to  become  dis- 
tinctly more  acid  in  the  contact  zone.  Space  was  made  for  them 
by  displacing  the  sedimentary  cover  and  by  a  marked  shortening 
of  the  sedimentary  rim  through  such  structures  as  overthrust 
faults  and  folds.  The  contact  is  observable  in  a  highly  meta- 
morphosed belt  about  twenty  feet  wide,  and  for  several  hundred 
feet  more  the  granite  has  absorbed  the  limestone  in  small  amounts 
with  the  production  of  new  minerals  and  the  development  of  a  dis- 
tinctly lighter  color.  The  deformative  effects  of  the  batholithic 
invasion  are  shown  in  their  gross  details  in  Figs.  141, 142,  and  146 ; 
the  finer  details  of  structure  are  represented  in  Fig.  147,  which  is 
drawn  from  a  measured  outcrop  above  Chuquibambilla. 

It  will  be  seen  that  we  have  here  more  than  a  mere  crinkling, 


222 


THE  ANDES  OF  SOUTHERN  PERU 


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Fig.  147 — Overthrust  folds  in  detail  on  the 
southwestern  border  of  the  Vilcapampa  hatho- 
lith  near  Chuquibambilla.  The  section  is  fifteen 
feet  high.  Elevation,  13,100  feet  (4,000  m.). 
For  comparison  with  the  structural  effects  of 
the  Vilcapampa  intrusion  on  the  northeast  see 
Fig.  142. 


such  as  the  mica  schists  of  the  Cordillera  Vilcapampa  display. 
The  diversified  sedimentary  series  is  folded  and  faulted  on  a  large 
scale  ^^'ith  broad  structural  undulations  visible  for  miles  along  the 
abrupt  valley  walls.  Here  and  there,  however,  the  strata  become 
weaker  generally  through  the  thinning  of  the  beds  and  the  more 
rapid  alternation  of  hard  and  soft  layers,  and  for  short  distances 

they  have  absorbed  notable 
amounts  of  the  stresses  in- 
duced by  the  igneous  intru- 
sions. In  such  places  not 
only  the  structure  but  the 
composition  of  the  rock 
shows  the  effects  of  the  in- 
trusion. Certain  shales  in 
the  section  are  carbonaceous 
and  in  all  observed  cases  the 
organic  matter  has  been 
transformed  to  anthracite,  a 
condition  generally  associated  with  a  certain  amount  of  minute 
mashing  and  a  cementation  of  both  limestone  and  sandstone. 

The  granite  becomes  notably  darker  on  approach  to  the  north- 
eastern contact  near  Colpani;  the  proportion  of  ferro-magnesian 
minerals  in  some  cases  is  so  large  as  to  give  a  distinctly  black 
color  in  sharp  contrast  to  the  nearly  white  granite  typical  of  the 
central  portion  of  the  mass.  Large  masses  of  shale  foundered  in 
the  invading  magma,  and  upon  fusion  gave  rise  to  huge  black 
masses  impregnated  with  quartz  and  in  places  smeared  or  in- 
jected with  granite  ma.gma.  Everywhere  the  granite  is  marked 
by  numbers  of  black  masses  which  appear  at  first  sight  to  be  ag- 
gregations of  dark  minerals  normal  to  the  granite  and  due  to  dif- 
ferentiation processes  at  tlic  time  of  crystallization.  It  is,  liow- 
cvfr.  noteworthy  tlmt  tlicso  increase  rapidly  in  number  on  ap- 
proacli  to  the  contact,  until  in  tlic  Inst  half-mile  they  appear  to 
grad<'  liitd  tlif  shale  inclusions.  It  ni;iy,  therefore,  be  doubted  that 
they  ar-e  nggregations.  Froni  tlH'ir  universal  distribution,  their 
uniform  character,  and  their  inaiked  increase  in  numbers  on  ap- 


EASTERN  ANDES:  CORDILLERA  VILCAPAMPA         223 

proach  to  lateral  contacts,  it  may  reasonably  be  inferred  that  they 
represent  foundered  masses  of  country  rock.  Those  distant  from 
present  contacts  are  in  almost  all  cases  from  a  few  inches  to  a 
foot  in  diameter,  while  on  approach  to  lateral  contacts  they  are 
in  places  ten  to  twenty  feet  in  width,  as  if  the  smaller  areas  rep- 
resented the  last  remnants  of  large  inclusions  engulfed  in  the 
magma  near  the  upper  or  roof  contact.  They  are  so  thoroughly 
injected  with  silica  and  also  with  typical  granite  magma  as  to 
make  their  reference  to  the  country  rock  less  secure  on  petro- 
graphical  than  on  purely  distributional  grounds. 

A  parallel  line  of  evidence  relates  to  the  distribution  of  com- 
plementary dikes  throughout  the  granite.  In  the  main  mass  of 
the  batholith  the  dikes  are  rather  evenly  distributed  as  to  kind 
with  a  slight  preponderance  of  the  dark-colored  group.  Near  the 
contact,  however,  aplitic  dikes  cease  altogether  and  great  num- 
bers of  melanocratic  dikes  appear.  It  may  be  inferred  that  we 
have  in  this  pronounced  condition  suggestions  of  strong  influence 
upon  the  final  processes  of  invasion  and  cooling  of  the  granite 
magma,  on  the  part  of  the  country  rock  detached  and  absorbed 
by  the  invading  mass.  It  might  be  supposed  that  the  indicated 
change  in  the  character  of  the  complementary  dikes  could  be 
ascribed  to  possible  differentiation  of  the  granite  magma  whereby 
a  darker  facies  would  be  developed  toward  the  Colpani  contact. 
It  has,  however,  been  pointed  out  already  that  the  darkening  of 
the  granite  in  this  direction  is  intimately  related  to  a  marked  in- 
crease in  the  number  of  inclusions,  leaving  little  doubt  that  the 
thorough  digestion  of  the  smaller  masses  of  detached  shales  is 
responsible  for  the  marked  increase  in  the  number  and  variety 
of  the  ferro-magnesian  and  special  contact  minerals. 

Upon  the  southwestern  border  of  the  batholith  the  number  of 
aplitic  dikes  greatly  increases.  They  form  prominent  features, 
not  only  of  the  granite,  but  also  of  the  schists,  adding  greatly  to 
the  strong  contrast  between  the  schist  of  the  border  zone  and  that 
outside  the  zone  of  metamorphism.  In  places  in  the  border 
schists,  these  are  so  numerous  that  one  may  count  up  to  twenty 
in  a  single  view,  and  they  range  in  size  from  a  few  inches  to  ten 


224  THE  ANDES  OF  SOUTHERN  PERU 

or  fifteen  feet.  The  greater  fissility  of  the  schists  as  contrasted 
with  the  shales  on  the  opposite  or  eastern  margin  of  the  batholith 
caused  them  to  be  relatively  much  more  passive  in  relation  to  the 
granite  magma.  They  were  not  so  much  torn  off  and  incorporated 
in  the  magma,  as  they  were  thoroughly  injected  and  metamor- 
phosed. Added  to  this  is  the  fact  that  they  are  petrographically 
more  closely  allied  to  the  granite  than  are  the  shales  upon  the 
northeastern  contact. 


CHAPTER  XIV 
THE  COASTAL  TERRACES 

AxoNG  the  entire  coast  of  Peru  are  upraised  and  dissected  ter- 
races of  marine  origin.    They  extend  from  sea  level  to  1,500  feet 
above  it,  and  are  best  displayed  north  of  Mollendo  and  in  the  des- 
ert south  of  Payta.    The  following  discussion  relates  to  that  por-  \ 
tion  of  the  coast  between  Mollendo  and  Camana.  1 

At  the  time  of  the  development  of  the  coastal  terraces  the  land 
was  in  a  state  of  temporary  equilibrium,  for  the  terraces  were  | 
cut  to  a  mature  stage  as  indicated  by  the  following  facts:  (1)  the 
terraces  have  great  mdth — from  one  to  five  and  more  miles;  (2) 
their  inner  border  is  straight,  or,  where  curves  exist,  they  are 
broad  and  regular;  (3)  the  terrace  tops  are  planed  off  smoothly 
so  that  they  now  have  an  even  gradient  and  an  almost  total  ab- 
sence of  rock  stacks  or  unreduced  spurs;  (4)  the  mature  slopes 
of  the  Coast  Eange,  strikingly  uniform  in  gradient  and  stage  of 
development  (Fig.  148),  are  perfectly  organized  with  respect  to 
the  inner  edge  of  the  terrace.  They  descend  gradually  to  the  ter- 
race margin,  showing  that  they  w^ere  graded  with  respect  to  sea 
level  when  the  sea  stood  at  the  inner  edge  of  the  highest  terrace. 

From  the  composition  and  even  distribution  of  the  thick-bed- 
ded Tertiary  deposits  of  the  desert  east  of  the  Coast  Eange,  it  is 
concluded  that  the  precipitation  of  Tertiary  time  was  greater  than 
that  of  today  (see  p.  261).  Therefore,  if  the  present  major  streams 
reach  the  sea,  it  may  also  be  concluded  that  those  of  an  earlier 
period  reached  the  sea,  provided  the  topography  indicates  the  per- 
fect adjustment  of  streams  to  structure.  Lacustrine  sediments 
are  absent  throughout  the  Tertiary  section.  Such  through-flowing 
streams,  discharging  on  a  stable  coast,  would  also  have  mature 
valleys  as  a  consequence  of  long  uninterrupted  erosion  at  a  fixed 
level.    The  Majes  river  must  have  cut  through  the  Coast  Eange 


^ 


226  THE  ANDES  OF  SOUTHERN  PERU 

at  Camana  then  as  now.  Likewise  the  Vitor  at  Quilca  must  have 
cut  straight  across  the  Coast  Eange.  An  examination  of  the  sur- 
face leading  down  from  the  Coast  Range  to  the  upper  edge  of 
these  valleys  fully  confiiTQS  this  deduction.  Flowing  and  well- 
graded  slopes  descend  to  the  brinlv  of  the  inner  valley  in  each 
case,  where  they  give  way  to  the  gorge  w^alls  that  continue  the 
descent  to  the  valley  floor. 

Confirmatory  evidence  is  found  in  the  wide  Majes  Valley  at 
Cantas  and  Aplao.  (See  the  Aplao  Quadrangle  for  details.) 
Though  the  observer  is  first  impressed  with  the  depth  of  the  val- 
ley, its  width  is  more  impressive  still.  It  is  also  clear  that  twO' 
periods  of  erosion  are  represented  on  its  walls.  Above  Aplao  the 
valley  walls  swing  off  to  the  west  in  a  great  embayment  quite  in- 
explicable on  structural  grounds;  in  fact  the  floor  of  the  embay- 
ment is  developed  across  the  structure,  which  is  here  more  dis- 
ordered than  usual.  The  same  is  true  below  Cantas,  as  seen  from 
the  trail,  which  drops  over  two  scarps  to  get  to  the  valley  floor. 
The  upper,  widely  opened  valley  is  correlated  with  the  latter  part 
of  the  period  in  which  were  formed  the  mature  terraces  of  the 
coast  and  the  mature  slopes  bordering  the  larger  valleys  where 
they  cross  the  Coast  Range. 

After  its  mature  development  the  well-graded  marine  terrace 
w^as  upraised  and  dissected.  The  deepest  and  broadest  incisions 
in  it  were  made  where  the  largest  streams  crossed  it.  Shallower 
and  narrower  valleys  were  formed  where  the  smaller  streams  that 
headed  in  the  Coast  Range  flowed  across  it.  Their  depth  and 
breadth  was  in  general  proportional  to  the  height  of  that  part  of 
the  Coast  Range  in  which  their  headwaters  lay  and  to  the  size  of 
their  catchment  basins. 

When  the  dissection  of  tlie  terrace  had  progressed  to  the  point 
where  about  one-third  of  it  liad  hoen  destroyed,  there  came  depres- 
sion and  tlic  dcposilioii  of  I  Miocene  or  early  Pleistocene  sands, 
gravels,  and  local  clay  beds.  l^A'orywhere  the  valleys  were  partly 
or  wholly  filled  and  o\-er  broad  stretches,  as  in  the  vicinity  of 
stream  mouths  and  n))on  lower  portions  of  the  terrace,  extensive 
deposits  were  laid  down.    The  largest  deposits  lie  several  hours' 


FiQ.   148. 


Fig.   149, 


Fig.  148 — The  Coast  Range  between  Mollendo  and  Arequipa  at  the  end  of  June, 
1911.  There  is  practically  no  grass  and  only  a  few  dry  shrubs.  The  fine  network  over 
the  hill  slopes  is  composed  of  interlacing  cattle  tracks.  The  cattle  roam  over  these 
hills  after  the  rains  which  come  at  long  intervals.  (See  page  141  for  description  of 
the  rains  and  the  transformations  they  effect.  For  example,  in  October,  1911,  these  hills 
were  covered  with  grass. ) 

Fig.  149 — The  great  marine  terrace  at  Mollendo.     See  Fig.  150  for  profile. 


THE  COASTAL  TERRACES 

ride  south  of  Camana,  where  locally  they 
attain  a  thickness  of  several  hundred  feet. 
Their  upper  surface  was  well  graded  and 
they  show  a  prolonged  period  of  deposi- 
tion in  which  the  former  coastal  terrace 
was  all  but  concealed. 

The  uplift  of  the  coast  terrace  and  its 
subsequent  dissection  bring  the  physical 
history  down  to  the  present.  The  uplift 
was  not  uniform ;  three  notches  in  the  ter- 
race show  more  faintly  upon  the  granite- 
gneiss  where  the  buried  rock  terrace  has 
been  swept  clean  again,  more  strongly 
upon  the  softer  superimposed  sand.  They 
lie  below  the  700-foot  contour  and  are  in- 
significant in  appearance  beside  the  slopes 
of  the  Coast  Range  or  the  ragged  bluff  of 
the  present  coast. 

The  effect  of  the  last  uplift  of  the  coast 
was  to  impel  the  Majes  River  again  to  cut 
down  its  lower  course  nearly  to  sea  level. 
The  Pliocene  terrace  deposits  are  here  en- 
tirely removed  over  an  area  several 
leagues  wide.  In  their  place  an  extensive 
delta  and  alluvial  fan  have  been  formed. 
At  first  the  river  undoubtedly  cut  down  to 
base  level  at  its  mouth  and  deposited  the 
cut  material  on  the  sea  floor,  now  shoal, 
for  a  considerable  distance  from  shore. 
We  should  still  find  the  river  in  that  posi- 
tion had  other  agents  not  intervened.  But 
in  the  Pleistocene  a  great  quantity  of 
waste  was  swept  into  the  Majes  Valley, 
whereupon  aggradation  began;  and  in  the 
middle  and  lower  valley  it  has  continued 
down  to  the  present. 


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228 


THE  ANDES  OF  SOUTHERN  PERU 


Vk.h.  ]r,[]r,i-~'\'hviii-  four  (liiignun.H  rrprcscnt  llm  pliyHioal  liialory  and  tho  corrc- 
Bpondinj?  physiographic  dfVfh)pTn.-nt  of  Ihn  .onsUil  ivfrj,,,,  „f  P.-ru  between  Cainanfi  and 
Mollendo.  The  scdim-ntary  beds  in  the  background  of  the  first  dii.grani  are  hyix)- 
theticnl  .'ind  are  supp.m.^d  to  correspond  t(.  tli.'  .pKnt/.it.'s  <,f  llie  Majes  Valley  at  Aplao. 


THE  COASTAL  TERRACES  229 

The  effect  lias  been  not  only  the  general  aggradation  of  the 
valley  floor,  but  also  the  development  of  a  combined  delta  and 
superimposed  alluvial  fan  at  the  valley  mouth.  The  seaward  ex- 
tension of  the  delta  has  been  hastened  by  the  gradation  of  the 
shore  between  the  bounding  headlands,  thus  giving  rise  to  marine 
marshes  in  which  every  particle  of  contributed  waste  is  firmly 
held.  The  plain  of  Camana,  therefore,  includes  parts  of  each  of 
the  following:  a  delta,  a  superposed  alluvial  fan,  a  salt-water 
marsh,  a  fresh-water  marsh,  a  series  of  beaches,  small  amounts 
of  piedmont  fringe  at  the  foot  of  Pliocene  deposits  once  trimmed 
by  the  river  and  by  waves,  and  extensive  tracts  of  indefinite  fill. 
(See  the  Camana  Quadrangle  for  details.) 

With  the  coastal  conditions  now  before  us  it  mil  be  possible 
to  attempt  a  correlation  between  the  erosion  features  and  the  de- 
posits of  the  coast  and  those  of  the  interior.  An  understanding 
of  the  comparisons  will  be  facilitated  by  the  use  of  diagrams. 
Figs.  151-154,  and  by  a  series  of  concise  summary  statements. 
From  the  relations  of  the  figure  it  appears  that : 

1.  The  Tertiary  deposits  bordering  the  Majes  Valley  east  of 
the  Coast  Range  were  in  process  of  deposition  when  the  sea 
planed  the  coastal  terrace  (Fig.  151). 

2.  A  broad  mature  marine  terrace  without  stacks  or  sharply 
alternating  spurs  and  reentrants  (though  the  rock  is  a  very  re- 
sistant granite)  is  correlated  with  the  mature  grades  of  the  Coast 
Range,  with  which  they  are  integrated  and  with  the  mature  pro- 
files of  the  main  Cordillera. 

3.  Such  a  high  degree  of  topographic  organization  requires 
the  dissection  in  the  late  stages  of  the  erosion  cycle  of  at  least 
the  inner  or  eastern  border  of  the  piedmont  deposits  of  the  des- 
ert, largely  accumulated  during  the  early  stages  of  the  cycle. 

4.  Since  the  graded  slopes  of  the  Coast  Range  on  the  one  side 
descend  to  a  former  shore  whose  elevation  is  now  but  1,500  feet 
above  sea  level,  and  since  only  ten  to  twenty  miles  inland  on  the 
other  side  of  the  range,  the  same  kind  of  slope  extends  beneath 
Tertiary  deposits  4,000  feet  above  sea  level,  it  appears  that  ag- 
gradation of  the  outer  (or  western)  part  of  the  Tertiary  deposits 


230  THE  ANDES  OF  SOUTHERN  PERU 

on  the  eastern  border  of  the  Coast  Range  continued  down  to  the 
end  of  the  cycle  of  erosion,  though 

5.  There  must  have  been  an  outlet  to  the  sea,  since,  as  we 
have  already  seen,  the  water  supply  of  the  Tertiary  was  greater 
than  that  of  today  and  the  present  streams  reach  the  sea.  More- 
over, the  mature  upper  slopes  and  the  steep  lower  slopes  of  the 
large  valleys  make  a  pronounced  topographic  unconformity,  show- 
ing two  cycles  of  valley  development. 

6.  Upon  uplift  of  the  coast  and  dissection  of  the  marine  ter- 
races at  the  foot  of  the  Coast  Range,  the  streams  cut  deep  trenches 
on  the  floors  of  their  former  valleys  (Fig.  152)  and  removed  (a) 
large  portions  of  the  coast  terrace,  and  (b)  large  portions  of  the 
Tertiary  deposits  east  of  the  Coast  Range. 

7.  Depression  of  the  coastal  terrace  and  its  partial  burial 
meant  the  drowning  of  the  lower  Majes  Valley  and  its  partial  fill- 
ing with  marine  and  later  with  terrestrial  deposits.  It  also 
brought  about  the  partial  filling  by  stream  aggradation  of  the 
middle  portion  of  the  valley,  causing  the  valley  fill  to  abut  sharply 
against  the  steep  valley  walls.     (See  Fig.  155.) 

8.  Uplift  and  dissection  of  both  the  terrace  and  its  overlying 
sediments  would  be  accompanied  by  dissection  of  the  former  val- 
ley fill,  provided  that  the  waste  supply  was  not  increased  and  that 
the  uplift  was  regional  and  approximately  equal  throughout — 
not  a  bowing  up  of  the  coast  on  the  one  hand,  or  an  excessive  bow- 
ing up  of  the  mountains  on  the  other.  But  the  waste  supply  has 
not  remained  constant,  and  the  uplift  has  been  greater  in  the 
Cordillera  than  on  the  coast.  Let  us  proceed  to  the  proof  of  these 
two  conclusions,  since  upon  them  depends  the  interpretation  of  the 
later  physical  history  of  the  coastal  valleys. 

It  is  known  llial  \\\c  I'lcistoceno  was  a  limo  of  jiugmented 
waste  delivery.  A\  llic  lic-id  of  llio  broadly  opened  Majes  Valley 
there  was  deposited  a  huge  mass  of  extremely  coarse  waste  sev- 
eral hundred  feet  doop  and  several  miles  long.  Forward  from  it, 
intorstratifiod  witli  its  outer  margin,  and  coutimiiug  the  same  al- 
luvial grade,  is  a  still  greater  mass  of  finer  material  whieh  de- 
scends to  lower  levels.    'I'lie  fine  ni;ite!-i;il  is  deposited  on  iho  floor 


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THE  COASTAL  TERRACES  231 

of  a  valley  cut  into  Tertiary  strata,  hence  it  is  younger  than  the 
Tertiary.  It  is  now,  and  has  been  for  some  time  past,  in  process 
of  dissection,  hence  it  was  not  formed  under  present  conditions  of 
climate  and  relief.  It  is  confidently  assigned  to  the  Pleistocene, 
since  this  is  definitely  known  to  have  been  a  time  of  greater  pre- 
cipitation and  waste  removal  on  the  mountains,  and  deposition  on 
the  plains  and  the  floors  of  mountain  valleys.  Such  a  conclusion 
appears,  even  on  general  grounds,  to  be  but  a  shade  less  reliable 
than  if  we  were  able  to  find  in  the  upper  Majes  Valley,  as  in  so 
many  other  Andean  valleys,  similar  alluvial  deposits  interlocked 
with  glacial  moraines  and  valley  trains. 

In  regard  to  the  second  consideration — the  upbowing  of  the 
Cordillera — it  may  be  noted  that  the  valley  and  slope  profiles  of 
the  main  Cordillera  sho^vn  on  p.  191,  when  extended  toward  the 
margin  of  the  mountain  belt,  lie  nearly  a  mile  above  the  level  of 
the  sea  on  the  west  and  the  Amazon  plains  on  the  east.  The  evi- 
dence of  regional  bowing  thus  afforded  is  checked  by  the  depths  of 
the  mountain  valleys  and  the  stream  profiles  in  them.  The 
streams  are  now  sunk  from  one  to  three  thousand  feet  below  their 
former  level.  Even  in  the  case  of  three  thousand  feet  of  erosion 
the  stream  profiles  are  still  ungraded,  the  streams  themselves  are 
almost  torrential,  and  from  one  thousand  to  three  thousand  feet 
of  vertical  cutting  must  still  be  accomplished  before  the  profiles 
will  be  as  gentle  and  regular  as  those  of  the  preceding  cycle  of 
erosion,  in  which  were  formed  the  mature  slopes  now  lying  high 
above  the  valley  floors. 

Further  evidence  of  bowing  is  afforded  by  the  attitude  of  the 
Tertiary  strata  themselves,  more  highly  inclined  in  the  case  of 
the  older  Tertiary,  less  highly  inclined  in  the  case  of  the  younger 
Tertiary.  It  is  noteworthy  that  the  gradient  of  the  present  val- 
ley floor  is  distinctly  less  than  that  of  the  least  highly  inclined 
strata.  This  is  true  even  where  aggradation  is  now  just  able  to 
continue,  as  near  the  nodal  point  of  the  valley,  above  Aplao, 
where  cutting  ceases  and  aggradation  begins.  (See  the  Aplao 
Quadrangle  for  change  of  function  on  the  part  of  the  stream 
a  half  mile   above   Cosos).     Such   a  progressive   steepening   of 


232  THE  ANDES  OF  SOUTHERN  PERU 

gradients  in  the  direction  of  the  oldest  deposits,  shows  very 
clearly  a  corresponding  progression  in  the  growth  of  the  Andes 
at  intervals  throughout  the  Tertiary. 

!  Thus  we  have  aggradation  in  the  Tertiary  at  the  foot  of  the 
growing  Andes ;  aggradation  in  the  Pliocene  or  early  Pleistocene 
on  the  floor  of  a  deep  valley  cut  in  earlier  deposits;  aggradation 
in  the  glacial  epoch;  and  aggradation  now  in  progress.  Basin 
deposits  within  the  borders  of  the  Peruvian  Andes  are  relatively 
rare.  The  profound  erosion  implied  by  the  development,  first  of 
a  mature  topography  across  this  great  Cordillera,  and  second  of 
many  deep  canyons,  calls  for  deposition  on  an  equally  great  scale 
on  the  mountain  borders.  The  deposits  of  the  western  border  are 
a  mile  thick,  but  they  are  confined  to  a  narrow  zone  between  the 
Coast  Range  and  the  Cordillera.  Whatever  material  is  swept  be- 
yond the  immediate  coast  is  deposited  in  deep  ocean  water,  for 
the  bottom  falls  off  rapidly.  The  deposits  of  the  eastern  border 
of  the  Andes  are  carried  far  out  over  the  Amazon  lowland.  Those 
of  earlier  geologic  periods  were  largely  confined  to  the  mountain 
border,  where  they  are  now  upturned  to  form  the  front  range  of 
the  Andes.  The  Tertiary  deposits  of  the  eastern  border  are  less 
restricted,  though  they  appear  to  have  gathered  chiefly  in  a  belt 
from  fifty  to  one  hundred  miles  wide. 

The  deposits  of  the  western  border  were  laid  down  by  short 
streams  rising  on  a  divide  only  100  to  200  miles  from  the  Pacific. 
Furthermore,  they  drain  the  dry  leeward  slopes  of  the  Andes. 
The  deposits  of  the  wet  eastern  border  were  made  by  far  larger 
streams  that  carry  the  waste  of  nearly  the  whole  Cordillera. 
Their  shoaling  effect  upon  the  Amazon  depression  must  have  been 
a  large  factor  in  its  steady  growth  from  an  inland  sea  to  a  river 
lowland. 


CHAPTER  XV 
PHYSIOGRAPHIC  AND   GEOLOGIC  DEVELOPMENT 

GEXERAL    FEATURES 

In  the  preceding  chapter  we  employed  geologic  facts  in  the 
determination  of  the  age  of  the  principal  topographic  forms. 
These  facts  require  further  discussion  in  connection  with  their 
closest  physiographic  allies  if  we  wish  to  show  how  the  topog- 
raphy of  today  originated.  There  are  many  topographic  details 
that  have  a  fundamental  relation  to  structure;  indeed,  without  a 
somewhat  detailed  knowledge  of  geology  only  the  broader  and 
more  general  features  of  the  landscape  can  be  interpreted.  In  this 
chapter  we  shall  therefore  refer  not  to  the  scenic  features  as  in  a 
purely  topographic  description,  but  to  the  rock  structure  and  the 
fossils.  A  complete  and  technical  geologic  discussion  is  not  de- 
sirable, first,  because  it  should  be  based  upon  much  more  detailed 
geologic  field  work,  and  second  because  after  all  our  main  pur- 
pose is  not  to  discuss  the  geologic  features  per  se,  but  the  physio- 
graphic background  which  the  geologic  facts  afford.  I  make  this 
preliminary  observation  partly  to  indicate  the  point  of  view  and 
partly  to  emphasize  the  necessity,  in  a  broad,  geographic  study, 
for  the  reconstruction  of  the  landscapes  of  the  past. 

The  two  dominating  ranges  of  the  Peruvian  Andes,  called  the 
Maritime  Cordillera  and  the  Cordillera  Vilcapampa,  are  com- 
posed of  igneous  rock — the  one  volcanic  lava,  the  other  intrusive  i\ 
granite.  The  chief  rock  belts  of  the  Andes  of  southern  Peru  are 
shown  in  Fig.  157.  The  Maritime  Cordillera  is  bordered  on  the 
west  by  Tertiary  strata  that  rest  unconformably  upon  Palaeozoic 
quartzites.  It  is  bordered  on  the  east  by  Cretaceous  limestones 
that  grade  downward  into  sandstones,  shales,  and  basal  conglom- 
erates. At  some  places  the  Cretaceous  deposits  rest  upon  old 
schists,   at   others   upon    Carboniferous   limestones    and   related i 

233 


234  THE  ANDES  OF  SOUTHERN  PERU 

strata,  upon  small  granite  intrusives  and  upon  old  and  greatly 
altered  volcanic  rock. 

/  The  Cordillera  ^'ilcapampa  lias  an  axis  of  granitic  rock  which 
/was  thrust  upward  through  schists  that  now  border  it  on  the  west 
and  slates  that  now  border  it  on  the  east.  The  slate  series  forms 
a  broad  belt  which  terminates  near  the  eastern  border  of  the 
Andes,  where  the  mountains  break  down  abruptly  to  the  river 
plains  of  the  Amazon  Basin.  The  immediate  border  on  the  east 
is  formed  of  vertical  Carboniferous  limestones.  The  narrow  foot- 
hill belt  is  composed  of  Tertiary  sandstones  that  grade  into  loose 
sands  and  conglomerates.  The  inclined  Tertiary  strata  were  lev- 
eled by  erosion  and  in  part  overlain  by  coarse  and  now  dissected 
river  gravels,  probably  of  Pleistocene  age.  Well  east  of  the  main 
border  are  low  ranges  that  have  never  been  described.  They 
could  not  be  reached  by  the  present  expedition  on  account  of  lack 
of  time.  On  the  extreme  western  border  of  that  portion  of  the 
Peruvian  Andes  herein  described,  there  is  a  second  distinct  border 
chain,  the  Coast  Range.  It  is  composed  of  granite  and  once  had 
considerable  relief,  but  erosion  has  reduced  its  former  bold  forms 
\  to  gentle  slopes  and  graded  profiles. 

The  continued  and  extreme  growth  of  the  Andes  in  later  geo- 
logic periods  has  greatly  favored  structural  and  physiographic 
studies.     Successive   uplifts   have   raised   earlier   deposits    once 
buried  on  the  mountain  flanks  and  erosion  has  opened  canyons  on 
whose  walls  and  floors  are  the  clearly  exposed  records  of  the  past. 
In  addition  there  have  been  igneous  intrusions  of  great  extent 
lliat  have  thrust  aside  and  upturned  tlie  invaded  strata  exposing 
still  furtlicr  the  internal  structures  of  the  mountains.    From  sec- 
lions  thus  r(!vealed  it  is  possible  to  outline  the  chief  events  in  the 
liistory  of  llie  Peruvian  Andes,  though  the  outline  is  still  neces- 
sarily broad  and  general  because  based  on  rapid  reconnaissance. 
/  However,  i1  shows  clcai-ly  lliat  tlic  landscape  ol"  llic  jjfcsent  reprc- 
[     sents  })iit  a  tcniporai-y  stage  in  llie  cNolnlioii  of  a  great  monntain 
belt.    At  ilie  (lawn  of  geologic  history  there  were  chains  of  nioun- 
^    tains  where  the  Andes  now  stand.     They  were  swept  away  and 
'  even   their  roots   deeply   submerged   under   invading   seas.     Re- 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      235 


Fig.  157 — Outline  sketch  sliowing  the 
principal  rock  bolts  of  Peru  along  the 
seventy-third  meridian.  They  are:  1, 
Pleistocene  and  Recent  gravels  and  sands, 
the  former  partly  indurated  and  slightly 
deformed,  with  the  degree  of  deformation 
increasing  toward  the  mountain  border 
(south).  2,  Tertiary  sandstones,  inclined 
from  15°  to  30°  toward  the  north  and 
unconformably  overlain  by  Pleistocene 
gravels.  3,  fossil-bearing  Carboniferous 
limestones  with  vertical  dip.  .),  non-fos- 
siliferous  slates,  shales,  and  slaty  schists 
(Silurian)  with  great  variation  in  degree 
of  induration  and  in  type  of  structure. 
South  of  the  parallel  of  1,3°  is  a  belt  of 
Carboniferous  limestones  and  sandstones 
bordering  (5)  the  granite  axis  of  the 
Cordillera  Vilcapampa.  For  its  structural 
relations  to  the  Cordillera  see  Figs.  141  and 
142.  6,  old  and  greatly  disturbed  volcanic 
agglomerates,  tuffs  and  porphyries,  and 
quartzitic  schists  and  granite-gneiss.  7, 
principally  Carboniferous  limestones  north 
of  the  axis  of  the  Central  Ranges  and 
Cretaceous  limestones  south  of  it.  Local 
granite  batholiths  in  the  axis  of  the  Central 
Ranges.  S,  quartzites  and  slates  predomi- 
nating with  thin  limestones  locally.  South 
of  8  is  a  belt  of  shale,  sandstone,  and  lime- 
stone with  a  basement  quartzite  appearing 
on  the  valley  floors.  9,  a  portion  of  the 
great  volcanic  field  of  the  Central  Andes 
and  characteristically  developed  in  the 
Western  or  Maritime  Cordillera,  through- 
out northern  Chile,  western  Bolivia,  and 
Peru.  At  Cotahuasi  (see  also  Fig.  20) 
Cretaceous  limestones  appear  beneath  the 
lavas.  10,  Tertiary  sandstones  of  the 
coastal  desert  with  a  basement  of  old  vol- 
canics  and  quartzites  appearing  on  the 
valley  walls.  The  valley  floor  is  aggraded 
with  Pleistocene  and  Recent  alluvium.  11, 
granite-gneiss  of  the  Coast  Range.  12,  late 
Tertiary  or  Pleistocene  sands  and  gravels 
deposited  on  broad  coastal  terraces.  For 
rock  structure  and  character  see  the  other 
figures  in  this  chapter.  For  a  brief  desig- 
nation of  index  fossils  and  related  forms 
see  Appendix  B.  For  the  names  of  the 
drainage  lines  and  the  locations  of  the 
principal  towns  see  Figs.  20  and  204. 


+   -t 
-h  + 


+    +  >H-4^C     -I-    -I-    4. 

<^  +^  +\+  +   Ci 


CIFIC  OCEAN 


236  THE  ANDES  OF  SOUTHERN  PERU 

peated  uplifts  of  the  earth's  crust  reformed  the  ancient  chains  or 
created  new  ones  out  of  the  rock  waste  derived  from  them.  Each 
new  set  of  forms,  therefore,  exhibits  some  features  transmitted 
from  the  past.  Indeed,  the  landscape  of  today  is  like  the  human 
race — inheriting  much  of  its  character  from  past  generations. 
For  this  reason  the  philosophical  study  of  topographic  forms  re- 
quires at  least  a  broad  knowledge  of  related  geologic  structures. 

SCHISTS   AND    SILUKIAN    SLATES  ^ 

I  The  oldest  series  of  rocks  along  the  seventy-third  meridian  of 
Peru  extends  eastward  from  the  Vilcapampa  batholith  nearly  to 
the  border  of  the  Cordillera,  Fig.  157.  It  consists  of  (1)  a  great 
mass  of  slates  and  shales  with  remarkable  uniformity  of  composi- 
tion and  structure  over  great  areas,  and  (2)  older  schists  and 
siliceous  members  in  restricted  belts.  They  are  everywhere  thor- 
oughly jointed;  near  the  batholith  they  are  also  mineralized  and 
altered  from  their  original  condition;  in  a  few  places  they  have 
been  intruded  with  dikes  and  other  form  of  igneous  rock. 

The  slates  and  shales  underlie  known  Carboniferous  strata  on 
their  eastern  border  and  appear  to  be  a  physical  continuation  of 
the  fossiliferous  slates  of  Bolivia;  hence  they  are  provisionally 
referred  to  the  Silurian,  though  they  may  possibly  be  Devonian. 
Certainly  the  known  Devonian  exceeds  in  extent  the  known 
Silurian  in  the  Central  Andes  but  its  lithological  character  is 
generally  quite  unlike  the  character  of  the  slates  here  referred  to 
the  Silurian.  The  schists  are  of  great  but  unknown  age.  They 
are  unconformably  overlain  by  known  Carboniferous  at  Pnquinra 
in  the  Vilcapampa  Valley  (Fig.  158),  and  near  Chuquibambilla  on 
the  opposite  side  of  the  Cordillera  Vilcapampa.  The  deeply 
wcalhcrod  fissile  mica  schists  east  of  Pasaje  (sec  Appendix  C  for 
iill  locations)  arc  also  unconformably  ovorl;ii]i  by  conglomerate 
and  sandstone  of  Carbonifcrons  Mge.  While  the  schists  vary  con- 
siderably in  lithological  appearance  and  also  in  structure,  they  are 
everywhere  the  lowest  rocks  in  the  series  and  may  with  confidence 

'For  a  list  of  tlu-   foHsilH   lli;i(.   form   the  \mn\H  of   tlio  iifji'   drtcrmin.'if  ions   in    this 
chapter  see  Appendix  B. 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      237 

be  referred  to  the  early  Palaeozoic,  while  some  of  them  may  date 
from  the  Proteriozoic. 

The  Silurian  beds  are  composed  of  shale,  sandstone,  shaly 
sandstone,  limestone,  and  slate  with  some  slaty  schist,  among 
which  the  shales  are  predominent  and  the  limestones  least  impor- 
tant. Near  their  contact  with  the  granite  the  slate  series  is  com- 
posed of  alternating  beds  of  sandstone  and  shale  arranged  in 
beds  from  one  to  three  feet  thick.     At  Santa  Ana  they  become 


Porphyry 


Fig.  158 — Geologic  sketch  map  of  tuu  lower  Urubaiaba  Valley.  A  single  traverse 
was  made  along  the  valley,  hence  the  boundaries  are  not  accurate  in  detail.  They  were 
sketched  in  along  a  few  lateral  traverses  and  also  inferred  from  the  topography. 
The  country  rock  is  schist  and  the  granite  intruded  in  it  is  an  arm  of  the  main 
granite  mass  that  constitutes  the  axis  of  the  Cordillera  Vilcapampa.  The  structure 
and  to  some  degree  the  extent  of  the  sandstone  on  the  left  are  represented  in  Figs. 
141  and  142. 


more  fissile  and  slaty  in  character  and  in  several  places  are  quar- 
ried and  used  for  roofing.  At  Eosalina  they  consist  of  almost 
uniform  beds  of  shale  so  soft  and  so  minutely  and  thoroughly 
jointed  as  to  weather  easily.  Under  prolonged  erosion  they  have, 
therefore,  given  rise  to  a  well-rounded  and  soft-featured  land- 
scape. Farther  down  the  Urubamba  Valley  they  again  take  on 
the  character  of  alternating  beds  of  sandstone  and  shale  from  a 
few  feet  to  fifteen  and  more  feet  thick.  In  places  the  metamor- 
phism  of  the  series  has  been  carried  further — the  shales  have  be- 
come slates  and  the  sandstones  have  been  altered  to  extremely  re- 
sistant quartzites.  The  result  is  again  clearly  sho"UTi  in  the  topog- 
raphy of  the  valley  wall  Avhich  becomes  bold,  inclosing  the  river 


238  THE  ANDES  OF  SOUTHERN  PERU 

in  narrow  '^pongos"  or  canyons  filled  with  huge  bowlders  and 
dangerous  rapids.  The  hills  become  mountains,  ledges  appear, 
and  even  the  hea\y  forest  cover  fails  to  smooth  out  the  natural 
ruggedness  of  the  landscape. 

It  is  only  upon  their  eastern  border  that  the  Silurian  series 
includes  calcareous  beds,  and  all  of  these  lie  within  a  few  thou- 
sand yards  of  the  contact  with  the  Carboniferous  limestones  and 
shales.  At  first  they  are  thin  paper-like  layers;  nearer  the  top 
they  are  a  few  inches  wide  and  finally  attain  a  thickness  of  ten 
or  twelve  feet.  The  available  limestone  outcrops  were  rigor- 
ously examined  for  fossils  but  none  were  found,  although  they 
are  lavishly  distributed  throughout  the  younger  Carboniferous 
beds  just  above  them.  It  is  also  remarkable  that  though  the 
Silurian  age  of  these  beds  is  reasonably  inferred  they  are  not 
separated  from  the  Carboniferous  by  an  unconformity,  at  least  we 
could  find  none  in  this  locality.  The  later  beds  disconformably 
overlie  the  earlier  beds,  although  the  sharp  differences  in  lithology 
and  fossils  make  it  easy  to  locate  the  line  of  separation.  The 
limestone  beds  of  the  Silurian  series  are  extremely  compact  and 
unfossiliferous.  At  least  in  this  region  those  of  Carboniferous 
age  are  friable  and  the  fossils  varied  and  abundant.  The  Silurian 
beds  are  everyAvhore  strongly  inclined  and  throughout  the  eastern 
half  or  third  of  their  outcrop  in  the  Urubamba  Valley  they  are 
nearly  vertical. 

In  view  of  the  enormous  thickness  of  the  repeated  layers  of 
shale  and  sandstone  this  series  is  of  great  interest.  Added  im- 
portance attaches  to  their  occurrence  in  a  long  belt  from  the 
eastern  edge  of  the  Bolivian  highlands  northward  through  Peru 
and  possibly  farther.  From  the  fact  that  their  disturbance  has 
Ixcii  oji  Ijroad  lines  over  wide  areas  witli  extreme  metamorphism, 
they  are  to  be  separated  Froiii  llie  oldei-  mica-schists  and  the 
cninipled  chlorite  schists  of  Puquiura  and  Pasaje.  I''in-lher  rea- 
sons for  this  distinction  lie  in  their  lithologic  difference  and,  to 
a  more  important  degree,  in  the  strong  unconfoi-niity  between  the 
Carboniferous  and  Ihe  schists  in  contrast  lo  the  disconformable 
relations   sliowu    between    IJic   Carbonifei-ous    and    Siliii-ian    fifty 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      239 

miles  away  at  Pongo  de  Mainique.  The  mashing  and  crumpling 
that  the  schists  have  experienced  at  Puquiura  is  so  intense,  that 
were  they  a  part  of  the  Silurian  series  the  latter  should  exhibit 
at  least  a  slight  unconformity  in  relation  to  the  Carboniferous 
limestones  deposited  upon  them. 

If  our  interpretation  of  the  relation  of  the  schists  to  the  slates 
and  shales  be  correct,  we  should  have  a  mountain-making  period 
introduced  in  pre-Silurian  time,  affecting  the  accumulated  sedi- 
ments and  bringing  about  their  metamorphism  and  crumpling  on 
a  large  scale.  From  the  mountains  and  uplands  thus  created  on 
the  schists,  sediments  were  washed  into  adjacent  waters  and  ac- 
cumulated as  even-bedded  and  extensive  sheets  of  sands  and  muds 
(the  present  slates,  shales,  quartzites,  etc.).  Nowhere  do  the  sedi- 
ments of  the  slate  series  show  a  conglomeratic  phase;  they  are 
remarkably  w^ell-sorted  and  consist  of  material  disposed  with 
great  regularity.  Though  they  are  coarsest  at  the  bottom  the 
lower  beds  do  not  show  cross-bedding,  ripple  marking,  or  other 
signs  of  shallow-water  conditions.  Toward  the  upper  part  of  the 
series  these  features,  especially  the  ripple-marking,  make  their 
appearance.  During  the  deposition  of  the  last  third  of  the  series, 
and  again  just  before  the  deposition  of  the  limestone,  the  beds 
took  on  a  predominantly  arenaceous  character  associated  with 
ripple  marks  and  cross-bedding  characteristic  of  shallow-water 
deposits. 

In  the  persistence  of  arenaceous  sediments  throughout  the 
series  and  the  distribution  of  the  ripple  marks  through  the  upper 
third  of  the  beds,  we  have  a  clear  indication  that  the  degree  of 
shallowness  was  sufficient  to  bring  the  bottom  on  which  the  sedi- 
ments accumulated  into  the  zone  of  current  action  and  possibly 
wave  action.  It  is  also  worth  considering  whether  the  currents 
involved  were  not  of  similar  origin  to  those  now  a  part  of  the 
great  counter-clockwise  movements  in  the  southern  seas.  If  so, 
their  action  would  be  peculiarly  effective  in  the  wide  distribution 
of  the  sediment  derived  from  a  land  mass  on  the  eastern  edge  of 
a  continental  coast,  since  they  would  spread  out  the  material  to 
a  greater  and  greater  degree  as  they  flowed  into  more  southerly 


240  THE  ANDES  OF  SOUTHERN  PERU 

latitudes.  Among  geologic  agents  a  broad  ocean  current  of 
relatively  uniform  flow  would  produce  the  most  uniform  effects 
throughout  a  geologic  period,  in  which  many  thousand  feet  of 
clastic  sediments  were  being  accumulated.  A  powerful  ocean  cur- 
rent would  also  work  on  flats  (in  contrast  to  the  gradient  re- 
quired by  near-shore  processes),  and  at  the  same  time  be  of  such 
deep  and  steady  flow  as  to  result  in  neither  ripple  marks  nor  cross- 
bedding. 

The  increasing  volume  of  shallow-water  sediments  of  uniform 
character  near  the  end  of  the  Silurian,  indicates  great  crustal 
stability  at  a  level  which  brought  about  neither  a  marked  gain 
nor  loss  of  material  to  the  region.  At  any  rate  we  have  here  no 
Devonian  sediments,  a  characteristic  shared  by  almost  all  the 
great  sedimentary  formations  of  Peru.  At  the  beginning  of  the 
Carboniferous  the  water  deepened,  and  great  heavy-bedded  lime- 
stones appear  with  only  thin  shale  partings  through  a  vertical  dis- 
tance of  several  hundreds  of  feet.  The  enormous  volume  of 
Silurian  sediments  indicates  the  deep  and  prolonged  erosion  of 
the  land  masses  then  existing,  a  conclusion  further  supported  (1) 
by  the  extensive  development  of  the  Silurian  throughout  Bolivia 
as  well  as  Peru,  (2)  by  the  entire  absence  of  coarse  material 
whether  at  the  top  or  bottom  of  the  section,  and  (3)  by  the  very 
limited  extent  of  older  rock  now  exposed  even  after  repeated  and 
irregular  uplift  and  deep  dissection.  Indeed,  from  the  latter  very 
striking  fact,  it  may  be  reasonably  argued  that  in  a  general  way 
the  relief  of  the  country  was  reduced  to  sea  level  at  the  close  of 
the  Silurian.  Over  the  perfected  grades  of  that  time  there  would 
then  be  afforded  an  opportunity  for  the  effective  transportation 
of  waste  to  the  extreme  limits  of  the  land. 

Further  evidence  of  the  great  reduction  of  surface  during  the 
Silurian  and  Devonian  is  supplied  by  the  extensive  development 
of  the  Carboniferous  strata.  Their  outcrops  are  now  scattered 
across  the  highor  portions  of  the  Andean  Cordillera  and  are  pre- 
vailingly calcareous  in  tlicir  upper  portions.  Upon  the  eastern 
border  of  the  Silurian  they  indicate  marine  conditions  from  the 
opening  of  the  period,  but  at  Pasajc  in  the  Apurimac  Valley  they 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      241 

are  marked  by  heavy  beds  of  basal  conglomerate  and  sandstone, 
and  an  abundance  of  ripple  marking  and  other  features  associated 
with  shallow-water  and  possibly  near-shore  conditions. 


CARBONIFEROUS 

Carboniferous  strata  are  distributed  along  the  seventy-third 
meridian  and  rival  in  extent  the  volcanic  material  that  forms  the 
western  border  of  the  Andes.  They  range  in  character  from 
basal  conglomerates,  sandstones,  and  shales  of  limited  develop- 
ment, to  enormous  beds  of  extremely  resistant  blue  limestone,  in 
general  well  supplied  with  fossils.    On  the  eastern  border  of  the 

FRONT  RANGE 


Fig.  159 — Topographic  and  structural  section  at  the  northeastern  border  of  the 
Peruvian  Andes.  The  slates  are  probably  Silurian,  the  fossiliferous  limestones  are 
known  Carboniferous,  and  the  sandstones  are  Tertiary  grading  up  to   Pleistocene. 

Andes  they  are  abruptly  terminated  by  a  great  fault,  the  continua- 
tion northward  of  the  marginal  fault  recognized  in  eastern 
Bolivia  by  Minchin^  and  farther  north  by  the  writer.^  Coarse 
red  sandstones  wath  conglomeratic  phase  abut  sharply  and  with 
moderate  inclination  against  almost  vertical  sandstones  and  lime- 
stones of  Carboniferous  age.  The  break  betw^een  the  vertical  lime- 
stones and  the  gently  inclined  sandstones  is  marked  by  a  promi- 
nent scarp  nearly  four  thousand  feet  high  (Fig.  159),  and  the 
limestone  itself  forms  a  high  ridge  through  which  the  Urubamba 
has  cut  a  narrow  gatew^ay,  the  celebrated  Pongo  de  Mainique. 

At  Pasaje,  on  the  western  side  of  the  Apurimac,  the  Carbonifer- 
ous again  appears  resting  upon  the  old  schists  described  on  p.  236. 
It  is  steeply  upturned,  in  places  vertical,  is  highly  conglomeratic, 
and  in  a  belt  a  half-mile  wide  it  forms  true  badlands  topography. 

*  Eastern  Bolivia  and  the  Gran  Chaco,  Proc.  Royal  Geogr.  Soc,  Vol.  3,  1881,  pp. 
401-420. 

•  The  Physiography  of  the  Central  Andes,  Am,  Journ.  Sci.,  Vol.  28,  1909,  p.  395. 


242 


THE  ANDES  OF  SOUTHERN  PERU 


^^ 

W; 

f         LIMESTOh 

E     \ 

>(!MESTONe/ 

\           \ 

\         \ 

^^^^> 

^m: 

Won? 

&>)     >A 

1 

\     \ 

It  is  succeeded  by  evenly  bedded  sandstones  of  fine  and  coarse 
composition  in  alternate  beds,  then  follow  shales  and  sandstones 
and  finally  the  enormous  beds  of  limestone  that  characterize  the 
series.  The  structure  is  on  the  whole  relatively  simple  in  this 
region,  the  character  and  attitude  of  the  beds  indicating  their  ac- 
cumulation in  a  nearly  horizontal  position.  Since  the  basal  con- 
glomerate contains  only  pebbles  and  stones  derived  from  the  sub- 
jacent schists  and  does  not  contain  granites  like  those  in  the  Cor- 
dillera Vilcapampa  batholith  on  the  east  it  is  concluded  that  the 

batholithic  invasion  was  ac- 
companied by  the  compression 
and  tilting  of  the  Carbonifer- 
ous beds  and  that  the  batholith 
itself  is  post-Carboniferous. 
From  the  ridge  summits  above 
Huascatay  and  in  the  deep 
valleys  thereabouts  the  Car- 
boniferous strata  may  be  seen 
to  extend  far  toward  the  west, 
and  also  to  have  groat  extent 
north  and  south.  Because  of 
their  dissected,  bare,  and,  therefore,  well-exposed  condition  they 
present  exceptional  opportunities  for  the  study  of  Carboniferous 
geology  in  central  Peru. 

Carboniferous  strata  again  appear  at  Puquiura,  Vilcapampa, 
and  Pampaconas.  They  are  sharply  upturned  against  tlie  Vilca- 
pampa batholith  and  associated  volcanic  material,  chiefly  basalt, 
porphyry,  and  various  luffs  and  related  breccias.  The  Carbonifer- 
ous beds  are  here  more  arenaceous,  consisting  cliiolly  of  alternat- 
ing beds  of  sandstone  and  shale.  The  lowermost  beds,  as  at 
Pongo  de  I^fainiquo,  are  dominantly  marine,  fossiliferous  lime- 
stone beds  having  a  thickness  estimated  lo  be  over  two  miles. 

From  TTuasf'jitay  westward  and  soutliwai'd  the  Carboniferous 
is  in  part  displaced  by  secondary  batlioliths  of  granite,  in  part 
cut  off  or  crowded  aside  by  igneous  intrusions  of  later  (ln1<',  and 
in  still  larger  part  l)iiricd  under  great  masses  of  Tertiary  volcanic 


M  s 

Fig.  160 — The  deformativo  eflfeets  of 
the  granite  intrusion  of  the  Cordillera 
Vilcapampa  are  hero  8ho\VTi  as  trans- 
mitted through  ancient  schists  to  the 
overlying  conglomerates,  sandstones,  and 
limestones  of  Carboniferous  agp,  in  the 
Apurimac  Valley   at  Pas^aje. 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      243 


Fig.  IGl — Types  of  deformation  north 
of  Lambraina  near  Sotospampa.  A 
dark  basaltic  rock  has  invaded  both 
granite-gneiss  and  slate.  Sills  and  dikes 
occur  in  great  numbers.  The  topographic 
depression  in  the  profile  is  the  Lambrama 
Valley.     See  the  Lambrama  Quadrangle. 


inateriaL  Nevertheless,  it  remains  the  dominating  rock  type  over 
the  whole  stretch  of  country  from  Huascatay  to  Huancarama.  In 
the  northwestern  part  of  the  Abancay  sheet  its  effect  on  the  land- 
scape may  be  observed  in  the 

knife-like  ridge  extending  from  ^^f77:7>'TA' 

west  to  east  just  above  Hu- 
ambo.  Above  Chuquibambilla 
it  again  outcrops,  resting  upon 
a  thick  resistant  quartzite  of 
unknown  age.  Fig.  162.  It  is 
strongly  developed  about 
Huadquirca  and  Antabamba 
and,  still  associated  with  a 
quartzite  floor,  it  finally  disap- 
pears under  the  lavas  of  the 

great  volcanic  field  on  the  western  border  of  the  Andes.  Figs.  141 
and  142  show  its  relation  to  the  invading  granite  batholiths  and 
Fig.  162  shows  further  structural  features  as  developed  about 
Antabamba  where  the  great  volcanic  field  of  the  Maritime  Cordil- 
lera begins. 

Both  the  enormous  thickness  of  the  Carboniferous  limestone 
series  and  the  absence  of  clastic  members  over  great  areas  in  the 

upper  portion  of  the  series 
prove  the  widespread  extent  of 
the  Carboniferous  seas  and  their 
former  occurrence  in  large  in- 
terlimestone  tracts  from  which 
they  have  since  been  eroded. 
At  Puquiura  they  extend  far 
over  the  schist,  in  fact  almost 
completely  conceal  it ;  at  Pasaje 
they  formerly  covered  the  mica- 
schists  extensively,  their  ero- 
sion in  both  cases  being  conditioned  by  the  pronounced  uplift  and 
marginal  deformation  which  accompanied  the  development  of  the 
Vilcapampa  batholith. 


Fig.  162 — Sketch  sections  at  Anta- 
bamba to  show  (a)  deformed  limestones 
on  the  upper  edge  of  the  geologic  map, 
Fig.  163  A;  and  (b)  the  structural  rela- 
tions of  limestone  and  quartzite.  See 
also  Fig.  163. 


244 


THE  ANDES  OF  SOUTHERN  PERU 


C  D 

Fig.  163 — Geologic  sketch  section  to 
show  the  relation  of  the  volcanic  flowa 
of  Fig.  104  to  the  sandstones  and  quart- 
zites  beneath. 


The  degree  of  deformation  of  the  Carboniferous  sediments 
varies  between  simple  uplift  through  moderate  folding  and  com- 
plex disturbances  resulting  in  nearly  vertical  attitudes.  The  sim- 
plest structures  are  represented  at  Pasaje,  where  the  uplift  of  the 

intruded  schists,  marginal  to 
the  Vilcapampa  batholith,  has 
produced  an  enormous  mono- 
clinal  fold  exposing  the  entire 
section  from  basal  conglomer- 
ates and  sandstones  to  the 
thickest  limestone.  Above  Chu- 
quibambilla  the  limestones  have 
been  uplifted  and  very  gently  folded  by  the  invasion  of  granite  as- 
sociated with  the  main  batholith  and  several  satollitic  batholiths  of 
limited  extent.  A  higher  degree  of  complexity  is  shoAvn  at  Pampa- 
conas  (Fig.  141),  where  the  main  monoclinal  fold  is  traversed  al- 
most at  right  angles  by  secondary  folds  of  great  amplitude.  The 
limestones  are  there  carried  to  the  limit  of  the  winter  snows  almost 
at  the  summit  of  the  Cordillera.  The  crest  of  each  secondary  anti- 
cline rises  to  form  a  group  of  conspicuous  peaks  and  tabular 
ridges.  Higher  in  the  section,  as  at  Puquiura,  the  sandstones  are 
thrown  into  a  series  of  huge  anticlines  and  synclines,  apparently 
by  the  marginal  compression  brought  about  at  the  time  of  the  in- 
trusion of  the  granite  core  of  the  range.  At  Pongo  de  Mainique 
the  whole  of  the  visible  Carboniferous  is  practically  vertical,  and 
is  cut  off  by  a  great  fault  marking  the  abrupt  eastern  border  of 
the  Cordillera. 

It  is  noteworthy  that  the  farther  east  the  Carboniferous  ex- 
tends the  more  dominantly  marine  it  becomes,  though  marine  beds 
of  great  thicltness  constitute  a  large  part  of  iho  series  in  what- 
ever location.  From  Huascatay  westward  the  limestones  become 
more  and  more  argillaceous,  and  finally  give  way  altogothor  to  an 
enormous  thickness  of  shales,  sandstones,  and  thin  conglomerates. 
These  were  observed  to  extend  with  strong  inclination  westward 
out  of  the  region  studied  and  into  and  under  the  volcanoes  crown- 
ing  the   western   border   of   the   Cordillera.     Along   the   line   of 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      245 


traverse  opportunity  was  not  afforded  for  further  study  of  this 
aspect  of  the  series,  since  our  route  led  generally  along  the  strike 
rather  than  along  the  dip  of  the  beds.  It  is  interesting  to  note, 
however,  that  these  observations  as  to  the  increasing  amounts  of 
clastic  material  in  a  westward  direction  were  afterwards  con- 
firmed by  Senor  Jose  Bravo,  the  Director  of  the  Bureau  of  Mines 
at  Lima,  who  had  found  Carboniferous  land  plants  in  shales  at 
Pacasmayo,  the  only  fossils  of 
their  kind  found  in  Peru.  For- 
merly it  had  been  supposed  that 
non-marine  Carboniferous  was 
not  represented  in  Peru.  From 
the  varied  nature  of  the  flora, 
the  great  thickness  of  the  shales 
in  which  the  specimens  were  col- 
lected, and  the  fact  that  the 
dominantly  marine  Carbonifer- 
ous elsewhere  in  Peru  is  of 
great  extent,  it  is  concluded  that 
the  land  upon  which  the  plants 
grew  had  a  considerable  area 
and  probably  extended  far  west 
of  the  present  coast  line.  Since 
its  emergence  it  has  passed 
through  several  orogenic  move- 
ments. These  have  resulted  in 
the  uplift  of  the  marine  portion 
of  the  Carboniferous,  while  the 
terrestrial  deposits  seem  to  have 
all  but  disappeared  in  the  down-sunken  blocks  of  the  ocean  floor, 
west  of  the  great  fault  developed  along  the  margin  of  the  Cordil- 
lera, The  following  figures  are  graphic  representations  of  this 
hypothesis. 

The  wide  distribution  of  the  Carboniferous  sediments  and 
especially  the  limestones,  together  with  the  uniformity  of  the  fos- 
sil faunas,  makes  it  certain  that  the  sea  extended  entirely  across 


A  B 

Fig.  164 — Geologic  sketch  map  and 
section,  Antabamba  region.  The  Anta- 
bamba  Riv(  r  has  cut  through  almost  the 
entire  series  of  bedded  strata. 


246 


THE  ANDES  OF  SOUTHERN  PERU 


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PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      247 

the  region  now  occupied  by  the  Andes.  However,  from  the  rela- 
tion of  the  Carboniferous  to  the  basal  schists,  and  the  most  con- 
servative extension  of  the  known  Carboniferous,  it  may  be  in- 
ferred that  the  Carboniferous  sea  did  not  completely  cover  the 
entire  area  but  was  broken  here  and  there  by  island  masses  in  the 
form  of  an  elongated  archipelago.  The  presence  of  land  plants 
in  the  Carboniferous  of  Pisco  warrants  the  conclusion  that  a  sec- 
ond island  mass,  possibly  an  island  chain  parallel  to  the  first,  ex- 
tended along  and  west  of  the  present  shore. 


EBMumm  ^limestoneQUIDSandstone  &  Shale  O  Volcanic 


CRETACEOUS 

The  Cretaceous  formations  are  of  very  limited  extent  in  the 
belt  of  country  under  consideration,  in  spite  of  their  generally 
wide  distribution  in  Peru.  They 
are  exposed  distinctly  only  on 
the  western  border  of  the  Cor- 
dillera and  in  special  relations. 
In  the  gorge  of  Cotahuasi,  over 
seven  thousand  feet  deep,  about 
two  thousand  feet  of  Cretaceous 
limestones  are  exposed.  The 
series  includes  only  a  very  re- 
sistant blue  limestone  and  ter- 
minates abruptly  along  a  well- 
marked  and  highly  irregular 
erosion  surface  covered  by  al- 
most a  mile  of  volcanic  ma- 
terial, chiefly  lava  flows.  The 
character  of  the  bottom  of  the 
section  is  likemse  unknown, 
since  it  lies  apparently  far  be- 
low the  present  level  of  ero- 
sion. 

The  Cretaceous  limestones  of  the  Cotahuasi  Canyon  are  every- 
where greatly  and  irregularly  disturbed.  Typical  conditions  are 
represented  in  the  maps  and  sections.  Figs.  166  and  167.    They  are 


Fig.  160 — Geologic  sketch  map  and 
cross-section  in  the  Cotahuasi  Canyon  at 
Cotahuasi.  With  a  slight  gap  this  figure 
continues  Fig.  167  to  the  left.  The  sec- 
tion represents  a  spur  of  the  irain  plateau 
about  1,500  feet  high  in  the  center  of  the 
map. 


248 


THE  ANDES  OF  SOUTHERN  PERU 


A 

^^-:':;:-:'::-^;":>^e-: 

^^B^ 

P 

_,__\ 

^1 

s 

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^^^ 

-^-■;:':-:-:- 

l:..-':;|Alluvluiii  II  |  lUfhickConqlandSandstiiiiep^Umeslone  gg^ Volcanic . 


penetrated  and  tilted  by  igneous  masses,  apparently  the  feeders 
of  the  great  lava  sheets  that  form  the  western  summit  of  the 
Cordillera.  From  the  restricted  development  of  the  limestones 
along  a  western  border  zone  it  might  be  inferred  that  they  rep- 
resent a  very  limited  marine  in- 
vasion. It  is  certainly  clear  that 
great  deformative  movements 
were  in  progress  from  at  least 
late  Palaeozoic  time  since  all  the 
Palaeozoic  deposits  are  broken 
abruptly  down  in  this  direction, 
and,  except  for  such  isolated  oc- 
currences as  the  land  Carbonif- 
erous at  Pacasmayo,  are  not 
found  anywhere  in  the  coastal 
region  today.     The  Cretaceous 

Fig.    167— Geologic    sketcl.    map    and  Jg     ^ot     OUly     limited     within     a 

cro3>-8ection  in  the  Cotahuasi  Canyon  ^.t  . 

Taurisma,  above  Cotahuasi.     The  relati  ns  relatively     UarrOW     shore     ZOUC, 

of  limestone  and  lava  flows  in  the  center  ^^t   also,    like    the    PallEOZoic,    it 

of  the  map   and  on   a   spur   lop   near   the  .■,■,■, 

canyon   floor.     Thousands  of   feet  of     ava  IS  broken  down  toward  the  West. 

extend  upward  from  the  flows  that  cap     ^Qt  reappearing  from  beneath 

the  limestone.  . 

the  Tertiary  cover  oi  the  desert 
region  or  upon  the  granite-gneisses  that  form  the  foundation  for 
all  the  known  sedimentary  strata  of  the  immediate  coast. 

From  these  considerations  I  tliink  we  have  a  strong  suggestion 
of  the  geologic  date  assignable  to  the  development  of  the  great 
fault  that  is  the  most  strongly  marked  structural  and  physio- 
graphic feature  of  the  west  coast  of  South  America.  Since  the 
development  of  this  fault  is  so  intimately  related  to  the  origin  of 
the  Pacific  Ocean  basin  its  study  is  of  special  importance.  The 
points  of  chief  interest  may  be  summarized  as  follows : 

(1)  The  character  of  the  land  Carboniferous  implies  a  much 
greater  extent  of  the  land  than  is  now  viRi])le. 

(2)  The  progressive  coarsening  of  the  Carboniferous  deposits 
westward  and  their  land  derivation,  together  with  the  great  thick- 
ness of  the  series,  point  to  an  elevated  laud  mass  in  process  of 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      249 

erosion  west  of  the  series  as  a  whole,  that  is  west  of  the  present 
coast. 

(3)  The  restricted  development  of  the  Cretaceous  seas  upon 
the  western  border  of  the  Carboniferous,  and  the  still  more  re- 
stricted development  of  the  Tertiary  deposits  between  the  moun- 
tains and  the  present  coast,  point  to  increasing  definition  of  the 
submarine  scarp  through  the  Mesozoic  and  the  Tertiary. 

(4)  The  Tertiary  deposits  are  all  clearly  derived  from  the 
present  mountains  and  have  been  washed  seaward  dovm  slopes 
with  geographic  relations  approximately  like  those  of  the  present. 

(5)  From  the  great  width,  deep  dissection,  and  subsequent 


Clays  and  sands. 

Red  sandstone  and  shale. 

Gray  and  yellow  sandstone  and  shale. 

'0 

Basal  sandstone. 
Volcanic  agglomerate. 
Volcanic   flows. 


Slaty  schist. 
Granite. 


Fig.  168 — Composite  structure  section  representing  the  succession  of  rocks  in  the 
Urubamba  Valley  from  Urubamba   to  Torontoy. 

burial  of  the  Tertiary  terraces  of  the  coast,  it  is  clear  that  the 
greater  part  of  the  adjustment  of  the  crust  to  which  the  bordering 
ocean  basin  is  due  was  accomplished  at  least  by  mid-Tertiary 
time. 

Aside  from  the  fossiliferous  limestones  of  kno^vn  Cretaceous 
age  there  have  been  referred  to  the  Cretaceous  certain  red  sand- 
stones and  shales  marked,  especially  in  the  central  portions  of  the 
Cordillera,  by  the  presence  of  large  amounts  of  salt  and  gypsum. 
These  beds  were  at  first  considered  Permian,  but  Steinmann  has 
since  found  at  Potosi  related  and  similar  formations  with  Creta- 
ceous fossils.  In  this  connection  it  is  also  necessary  to  add  that 
the  great  red  sandstone  series  forming  the  eastern  border  of  the 
Andes  in  Bolivia  is  of  uncertain  age  and  has  likewise  been  re- 


250  THE  ANDES  OF  SOUTHERN  PERU 

ferred  to  the  Cretaceous,  though  the  matter  of  its  age  has  not  yet 
been  definitely  determined.  In  1913  I  found  it  appearing  in  north- 
western Argentina  in  the  Calchaqui  Valley  in  a  relation  to  the 
main  Andean  mass,  similar  to  that  displayed  farther  north.  It 
contains  fossils  and  its  age  was,  therefore,  readily  determinable 
there.* 

In  the  Peruvian  field  the  red  beds  of  questionable  age  were  not 
examined  in  sufficient  detail  to  make  possible  a  definite  age  de- 
termination. They  occur  in  a  great  and  only  moderately  disturbed 
series  in  the  Anta  basin  north  of  Cuzco,  but  are  there  not  fos- 
siliferous.  The  northeastern  side  of  the  hill  back  of  Puqura  (of 
the  Anta  basin:  to  be  distinguished  from  Puquiura  in  the  Vilca- 
bamba  Valley)  is  composed  largely  of  rocks  of  this  class.  In  a 
few  places  their  calcareous  members  have  been  weathered  out  in 
such  a  manner  as  to  show  karst  topography.  Where  they  occur 
on  the  well-drained  brow  of  a  bluff  the  caves  are  used  in  place 
of  houses  by  Indian  farmers.  The  large  and  strikingly  beautiful 
Lake  Huaipo,  ten  miles  north  of  Anta,  and  several  smaller,  neigh- 
boring lakes,  appear  to  have  originated  in  solution  depressions 
formed  in  these  beds. 

The  structural  relation  of  the  red  sandstone  series  to  the  older 
rocks  is  well  displayed  about  half-way  between  Urubamba  and 
Ollantaytambo  in  the  deep  Urubamba  Valley.  The  basal  rocks  are 
slaty  schist  and  granite  succeeded  by  agglomerates  and  basalt  por- 
phyries upon  whose  eroded  surfaces  (Fig.  169)  are  gray  to  yel- 
low cross-bedded  sandstones.  Within  a  few  hundred  feet  of  the 
unconformity  gypsum  deposits  begin  to  appear  and  increase  in 
number  to  such  an  extent  that  the  resulting  soil  is  in  places  ren- 
dered worthless.  Copper-stained  bands  are  also  common  near  the 
bottom  of  the  series,  but  these  are  confined  to  the  lower  beds. 
Higher  up  in  the  section,  for  example,  just  above  the  gorge  between 
Urubamba  nnd  011.-mlaytani])o,  ovon-bedded  sandstones  occur 
whose  most  prominent  characteristic  is  the  regular  succession  of 

*  See  pnpor  by  TT.  S.  Pnlmor,  my  naHifltant  on  tlm  Expodition  to  Ihe  rontrnl  Andoa, 
1913,  entitlpfl:  CJcologicnl  Notx>8  on  the  vVndfH  of  NortliwfHtcrn  Argentina,  Am.  Joiirn. 
Sci.,  Vol.  38,  ini4,  pp.  309  3.30. 


y^:f^:ii;.;:v^;^T^'i5^;^?p:4s^^ 


■=•5' « -r'*'.'' 


7^ J   :r:.^^~^,V^•.^'^^■•.c;■'^.. 

..-.^      v,;.v  ..;■; 


Fig.   169. 


Fig.    170. 

Fig.  169 — The  line  of  unconformity  between  the  igneous  basement  rocks  (agglom- 
erates at  this  point)  and  the  quartzites  and  sandstones  of  the  Urubamba  Valley, 
between   the  town   of   Urubamba  and  OUantaytambo. 

Fig.  170 — The  inclined  lower  and  horizontal  upper  sandstone  on  the  southeastern 
wall  of  the  Majes  Valley  at  Hacienda  Cantas.     The  section  is  a  half-mile  high. 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      251 

coarse  and  fine  sandstone  beds.  Such  alternations  of  character  in 
sedimentary  rocks  are  commonly  marked  by  alternating  shales 
and  sandstones,  but  in  this  locality  shales  are  practically  absent. 
Toward  the  top  of  the  section  gypsum  deposits  again  appear  first 
as  beds  and  later,  as  in  the  case  of  the  hill-slope  on  the  southern 
shore  of  Lake  Huaipo,  as  veins  and  irregular  masses  of  gypsum. 
The  top  of  the  deformed  Cretaceous  (?)  is  eroded  and  again  cov- 
ered unconformably  by  practically  flat-lying  Tertiary  deposits. 

TERTIARY 

The  Tertiary  deposits  of  the  region  under  discussion  are 
limited  to  three  regions:  (1)  the  extreme  eastern  border  of  the 
main  Cordillera,  (2)  intermontane  basins,  the  largest  and  most 
important  of  which  are  (a)  the  Cuzco  basin  and  (b)  the  Titicaca- 
Poopo  basin  on  the  Peruvian-Bolivian  frontier,  and  (3)  in  the 
west-coast  desert  and  in  places  upon  the  huge  terraces  that  form 
a  striking  feature  of  the  topography  of  the  coast  of  Peru. 

It  has  already  been  pointed  out  that  the  eastern  border  of  the 
Cordillera  is  marked  by  a  fault  of  great  but  undetermined  throw, 
whose  topographic  importance  may  be  estimated  from  the  fact 
that  even  after  prolonged  erosion  it  stands  nearly  four  thousand 
feet  high.  Cross-bedded  and  ripple-marked  features  and  small 
lenses  of  conglomerate  are  common.  The  beds  now  dip  at  an 
angle  approximately  20°  to  50°  northward  at  the  base  of  the  scarp, 
but  have  decreasing  dip  as  they  extend  farther  north  and  east. 
It  is  noteworthy  that  the  deposits  become  distinctly  conglomeratic 
as  flatter  dips  are  attained,  and  that  there  seems  to  have  been  a 
steady  accumulation  of  detrital  material  from  the  mountains  for 
a  long  period,  since  the  deposits  pass  in  unbroken  succession  from 
the  highly  indurated  and  massive  beds  of  the  mountain  base  to 
loose  conglomerates  that  now  weather  down  much  like  an  ordi- 
nary gravel  bank.  In  a  few  places  just  below  the  mouth  of  the 
Ticumpinea,  logs  about  six  inches  in  diameter  were  observed 
embeded  in  the  deposits,  but  these  belong  distinctly  to  the  upper 
horizons. 

The  border  deposits,  though  they  vary  in  dip  from  nearly  flat 


252  THE  ANDES  OF  SOUTHERN  PERU 

to  50°,  are  everj-^vhere  somewhat  inclined  and  now  lie  up  to  sev- 
eral hundred  feet  above  the  level  of  the  Urubamba  River.  Their 
upper  surface  is  moderately  dissected,  the  degree  of  dissection  be- 
ing most  pronounced  where  the  dips  are  steepest  and  the  height 
greatest.  In  fact,  the  attitude  of  the  deposits  and  their  progres- 
sive change  in  character  point  toward,  if  they  do  not  actually 
prove,  the  steady  and  progressive  character  of  the  beds  first  de- 
posited and  their  erosion  and  redeposition  in  beds  now  higher  in 
the  series. 

Upon  the  eroded  upper  surfaces  of  the  inclined  border  de- 
posits, gravel  beds  have  been  laid  which,  from  evidence  discussed 
in  a  later  paragraph,  are  without  doubt  referable  to  the  Pleis- 
tocene. These  in  turn  are  now  dissected.  They  do  not  extend  to 
the  highest  summits  of  the  deformed  beds  but  are  confined,  so 
far  as  observations  have  gone,  to  elevations  about  one  hundred 
feet  above  the  river.  From  the  evidence  that  the  overlying  hori- 
zontal beds  are  Pleistocene,  the  thick,  inclined  beds  are  referred 
to  Tertiary  age,  though  they  are  nowhere  fossiliferous. 

Observations  along  the  Urubamba  River  were  extended  as  far 
northward  as  the  mouth  of  the  Timpia,  one  of  the  larger  tribu- 
taries. Upon  returning  from  this  point  by  land  a  wide  view  of 
the  country  was  gained  from  the  four-thousand-foot  ridge  of 
vertical  Carboniferous  limestone,  in  which  it  appeared  that  low 
and  irregular  strike  ridges  continue  the  features  of  the  Tertiary 
displayed  along  the  mountain  front  far  northward  as  well  as  east- 
ward, to  a  point  where  the  higher  ridges  and  low  mountains  of 
older  rock  again  appear — the  last  outliers  of  the  Andean  system 
in  Peru.  Unfortunately  time  enough  was  not  available  for  an  ex- 
tension of  the  trip  to  these  localities  whose  geologic  characters 
still  remain  entirely  unknown.  From  the  topographic  aspects  of 
tlie  country,  it  is,  however,  reasonably  certain  that  the  whole  in- 
tervening depression  between  these  outlying  ranges  and  the 
border  of  the  main  Cordillera,  is  filled  with  inclined  and  now  dis- 
sected and  partly  covered  Tertiary  strata.  The  elevation  of  the 
upper  surface  does  not,  however,  remain  the  same;  it  appears  to 
decrease   steadily  and   the  youngest  Tertiary   strata  disappear 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      253 

from  view  below  the  sediments  of  either  the  Pleistocene  or  the 
present  river  gravels.  In  the  more  central  parts  of  the  depres- 
sion occupied  by  the  Urubamba  Valley,  only  knobs  or  ridges  pro- 
ject here  and  there  above  the  general  level. 

The  Coastal  Tertiary 

The  Tertiary  deposits  of  the  Peruvian  desert  region  southwest 
of  the  Andes  have  many  special  features  related  to  coastal  de- 
formation, changes  of  climate,  and  great  Andean  uplifts.  They 
lie  between  the  west  coast  of  Peru  at  Camana  and  the  high,  lava- 
covered  country  that  forms  the  western  border  of  the  Andes  and 
in  places  are  over  a  mile  thick.  They  are  non-fossiliferous,  cross- 
bedded,  ripple-marked,  and  have  abundant  lenses  of  conglomerate 
of  all  sizes.  The  beds  rest  upon  an  irregular  floor  developed  upon 
a  varied  mass  of  rocks.  In  some  places  the  basement  consists  of 
old  strata,  strongly  deformed  and  eroded.  In  other  places  it  con- 
sists of  a  granite  allied  in  character  and  probably  in  origin  Avith 
the  old  granite-gneiss  of  the  Coast  Range  toward  the  west.  Else- 
where the  rock  is  lava,  evidently  the  earliest  in  the  great  series 
of  volcanic  flows  that  form  this  portion  of  the  Andes. 

The  deposits  on  the  western  border  of  the  Andes  are  excel- 
lently exposed  in  the  Majes  Valley,  one  of  the  most  famous  in 
Peru,  though  its  fame  rests  rather  upon  the  excellence  and  abun- 
dance of  its  vineyards  and  wines  than  its  splendid  geologic  sec- 
tions. Its  head  lies  near  the  base  of  the  snow-capped  peaks  of 
Coropuna;  its  mouth  is  at  Camana  on  the  Pacific,  a  hundred  miles 
north  of  Mollendo.  It  is  both  narrow  and  deep;  one  may  ride 
across  its  floor  anywhere  in  a  half  hour.  In  places  it  is  a  narrow 
canyon.  Above  Cantas  it  is  sunk  nearly  a  mile  below  the  level  of 
the  desert  upland  through  which  it  flows.  Along  its  borders  are 
exposed  basal  granites,  old  sedimentaries,  and  lavas ;  inter-bedded 
with  it  are  other  lavas  that  lie  near  the  base  of  the  great  volcanic 
series;  through  it  still  project  the  old  granites  of  the  Coast 
Range;  and  upon  it  have  been  accumulated  additional  volcanic 
rocks,  wind-blo^\Ti  deposits,  and,  finally,  coarse  wash  formed  dur- 
ing the  glacial  period.    From  both  the  variety  of  the  formations. 


254.  THE  ANDES  OF  SOUTHERN  PERU 

the  small  amount  of  marginal  dissection,  and  the  excellent  expo- 
sures made  possible  by  the  deep  erosion  and  desert  climate,  the 
Majes  Valley  is  one  of  the  most  profitable  places  in  Peru  for 
physiographic  and  geologic  study. 

The  most  complete  succession  of  strata  (Tertiary)  occurs  just 
below  Cantas  on  the  trail  to  Jaguey  (Fig.  171).  Upon  a  floor  of 
granite-g-neiss,  and  alternating  beds  of  quartzite  and  shale  belong- 


COASTAL    DESERT  MARITIME   CORDILLERA 


Fig.  171 — Generalized  sketch  section  to  sliow  the  structural  relations  of  the  Mari- 
time Cordillera,   the   desert  pampas,   and  the  Coast  Range. 

ing  to  an  older  series,  are  deposited  heavy  beds  of  red  sandstone 
with  many  conglomerate  lenses.  The  sandstone  strata  are  meas- 
urably deformed  and  their  upper  surfaces  moderately  dissected. 
Upon  them  have  been  deposited  unconformably  a  thicker  series 
of  deposits,  conglomerates,  sandstones,  and  finer  mnd-blown  ma- 
terial. The  basal  conglomerate  is  very  coarse— much  like  beach 
material  in  both  structure  and  composition,  and  similar  to  that 
along  and  south  of  the  present  coast  at  Camana.  Higher  in  the 
section  the  material  is  prevailingly  sandy  and  is  deposited  in 
regular  beds  from  a  few  inches  to  a  few  feet  in  thickness.  Near 
the  top  of  the  section  are  a  few  hundred  feet  of  strata  chiefly  wind 
deposited.  Unconformably  overlying  the  whole  series  and  in 
sliarp  contrast  to  the  fine  wind-blown  stuff  below  it,  is  a  third 
series  of  coarse  deposits  about  five  hundred  feet  thick.  The  top- 
most material,  that  forming  the  surface  of  llic  desert  upland,  con- 
sists of  wind-blown  sand  now  shifted  by  the  wind  and  gathered 
into  sand  dunes  or  irregular  drifts,  banks  of  white  earth,  "tierra 
])lanea,"  and  a  pebble  pavement  a  few  inches  thick. 

If  the  main  facts  of  the  above  section  are  now  summarized 
they  will  facilitate  an  understanding  of  other  sections  about  to  be 
described,  inasmuch  as  the  summary  will  in  a  measure  anticipate 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      255 


our  conclusions  concerning  the  origin  of  the  deposits  and  their 
subsequent  history.  The  sediments  in  the  Majes  Valley  between 
Cantas  and  Jaguey  consist  of  three  series  separated  by  two  un- 
conformities. The  lowermost  series  is  evenly  bedded  and  rather 
uniform  in  composition  and  topographic  expression,  standing 
forth  in  huge  cliffs  several  hundred  feet  high  on  the  eastern  side 


ILO 

COAST     RANOE 
LRS    LOMOS 

LA  RINCONAOA 

LAS    PAMPAS 

MOQUEGUA 

SIERR.A 

..<*=■ 

:i'^ 

^^ 

-.^ 

■^         STRUCTURE 

VHUHOVIH 

sen  ixvEL — 

Fig.  172 — Geologic  relations  of  Coast  Range,  desert  deposits,  and  Maritime 
Cordillera  at  Moquegua,  Peru.  After  G.  I.  Adams;  Bol.  de  Minas  del  Perfl,  Vol.  2, 
Ko.  4,  1906,  p.  20. 

of  the  valley.  This  lower  series  is  overlain  by  a  second  series, 
which  consists  of  coarse  conglomerate  grading  into  sand  and  ulti- 
mately into  very  fine  fluffy  wind-deposited  sands  and  silts.  The 
lower  series  is  much  more  deformed  than  the  upper,  showing  that 
the  deforming  movements  of  later  geologic  times  have  been  much 
less  intense  than  the  earlier,  as  if  there  had  been  a  fading  out  or 
weakening  of  the  deforming  agents.  Finally  there  is  a  third 
series  several  hundred  feet  thick  which  forms  the  top  of  the 
section. 

Three  other  sections  may  now  be  examined,  one  immediately 
below  Cantas,  one  just  above,  and  one  opposite  Aplao.  The  sec- 
tion below  Cantas  is  shoT\Ti 
in  Fig.  173,  and  indicates 
a  lower  series  of  red  sand- 
stones crossed  by  vertical 
faults  and  unconformably 
overlain    bv     nearlv     hori- 


FiG.  173 — Sketch  section  to  show  structural 
details  on  the  walls  of  the  Majes  Valley  near 
Aplao,  looking  south. 


zontal  conglomerates,  sandstones,  etc.,  and  the  whole  faulted  again 
with  an  inclined  fault  ha^dng  a  throw  of  nearly  25°.  A  white  to 
gray  sandstone  unconformably  overlying  the  red  sandstone  is 
sho^vn  interpolated  between  the  lowermost  and  uppermost  series, 
the  only  example  of  its  kind,  however.     No  important  differences 


256  THE  ANDES  OF  SOUTHERN  PERU 

in  lithographical  character  may  be  noted  between  these  and  the 
beds  of  the  preceding  section. 

Again  just  above  Cantas  on  the  east  side  of  the  valley  is  a 
clean  section  exposing  about  two  thousand  feet  of  strata  in  a  half 
mile  of  distance.  The  foundation  rocks  are  old  quartzites  and 
shales  in  regularly  alternating  beds.  Upon  their  uneven  upper 
surfaces  are  several  thousand  feet  of  red  sandstones  and  conglom- 
erates, which  are  both  folded  and  faulted  with  the  underlying 
quartzites.  Above  the  red  sandstones  is  a  thick  series  of  gray 
sandstones  and  silts  w^hich  makes  the  top  of  the  section  and  uncon- 
formably  overlies  the  earlier  series. 

A  similar  succession  of  strata  was  observed  at  Aplao,  still 
farther  up  the  Majes  Valley,  Fig.  174.  A  greatly  deformed  and 
metamorphosed  older  series  is  unconformably  overlaid  by  a  great 


FiQ.  174 — The  structural  relations  of  the  strata  on  the  border  of  the  Majes  Valley 
at  Aplao,  looking  west.  Field  sketch  from  opposite  side  of  valley.  Height  of  section 
about  3,000  feet;   length  about  ten  miles. 

thickness  of  younger  strata.  The  younger  strata  may  be  again 
divided  into  two  series,  a  lower  series  consisting  chiefly  of  red 
sandstones  and  an  upper  consisting  of  gray  to  yellow,  and  only 
locally  red  sands  of  finer  texture  and  more  uniform  composition. 
The  two  are  separated  by  an  erosion  surface  and  only  the  upper 
series  is  tilted  regionally  seaward  with  faint  local  deformation; 
the  lower  series  is  both  folded  and  faulted  with  overthrusts  ag- 
gregating several  thousand  feet  of  vertical  and  a  half  mile  of 
horizontal  displacement. 

The  above  sections  all  lie  on  the  eastern  side  of  the  Majes  Val- 
ley. From  the  upper  edge  of  the  valley  extensive  views  were 
gained  of  the  strata  on  the  opposite  side,  and  two  sections,  though 
they  were  not  examined  at  close  range,  arc  at  least  worth  com- 
paring witli  those  already  given.  From  the  narrows  below  Can- 
tas the  structure  appears  as  in  Figs.  175-17fi,  and  shows  a  deform- 
ing movement  succeeded  by  erosion  in  ;i  lower  series.    The  upper 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      257 

series  of  sedimentary  rock  has  suffered  but  slight  deformation. 
A  still  more  highly  deformed  basal  series  occurs  on  the  right  of 
the  section,  presumably  the  older  quartzites.  At  Huancarqui,  op- 
posite Aplao,  an  extensive  view  was  gained  of  the  western  side 


^ zUPPER^ANDSTONE^SERIESJ 

LOWER  SANDSTONE    SERIES         ^\vWHIT[  AND  GRLY    ^-«ED- 


FiG.  175 — Sketch  section  to  show  the  structural  details  of  the  strata  on  the  south 
wall  of  the  Majes  Valley  near  Cantas.     The  section  is  two  miles  long. 

of  the  valley,  but  the  lower  Tertiary  seems  not  to  be  represented 
here,  as  the  upper  undeformed  series  rests  unconformably  upon 
a  tilted  series  of  quartzites  and  slates.  Farther  up  the  Cantas 
valley  (an  hour's  ride  above  Aplao)  the  Tertiary  rests  upon  vol- 
canic flows  or  older  quartzites  or  the  granite-gneiss  exposed  here 
and  there  along  the  valley  floor. 

In  no  part  of  the  sedimentaries  in  the  Majes  Valley  were  fos- 
sils found,  save  in  the  now  uplifted  and  dissected  sands  that  over- 
lie the  upraised  terraces  along  the  coast  immediately  south  of 


Fig.  176 — Composite  geologic  section  to  show  the  structural  relations  of  the 
rocks  on  the  western  border  of  the  Maritime  Cordillera.  The  inclined  strata  at  the 
right  bottom   represent   older   rocks;    in   places  igneous,   in   other   places   sedimentary. 

Camana  and  also  back  of  Mollendo.  Like  similar  coastal  deposits 
elsewhere  along  the  Peruvian  littoral,  the  terrace  sands  are  of 
Pliocene  or  early  Pleistocene  age.  The  age  of  the  deposits  back 
of  the  Coast  Range  is  clearly  greater  than  that  of  the  coastal  de- 
posits, (1)  since  they  involve  two  unconformities,  a  mile  or  more 
of  sediments,  and  now  stand  at  least  a  thousand  feet  above  the 
highest  Pliocene  (or  Pleistocene)  in  the  Camana  Valley,  and  (2) 
because  the  erosion  history  of  the  interior  sediments  may  be  cor- 
related with  the  physiographic  history  of  the  coastal  terraces  and 
the  correlation  shows  that  uplift  and  dissection  of  the  terraces 
and  of  the  interior  deposits  went  hand  in  hand,  and  that  the  de- 


258  THE  ANDES  OF  SOUTHERN  PERU 

posits  on  the  terraces  may  similarly  be  correlated  with  alluvial 
deposits  in  the  valley. 

We  shall  now  see  what  further  ground  there  is  for  the  de- 
termination of  the  age  of  these  sediments.  Just  below  Chuqui- 
bamba,  where  they  first  appear,  the  sediments  rest  upon  a  floor  of 
volcanic  and  older  rock  belonging  to  the  great  field  now  known 
from  evidence  in  many  localities  to  have  been  formed  in  the  early 
Tertiary,  and  here  known  to  be  post-Cretaceous  from  the  rela- 
tions between  Cretaceous  limestones  and  volcanics  in  the  Cota- 
huasi  Valley  (see  p.  247).  Although  volcanic  flows  were  noted 
interbedded  with  the  desert  deposits,  these  are  few  in  number,  in- 
significant in  volume,  and  belong  to  the  top  of  the  volcanic  series. 
The  same  may  be  said  of  the  volcanic  flows  that  locally  overlie 
the  desert  deposits.  We  have  then  definite  proof  that  the  sand- 
stones, conglomerates,  and  related  formations  of  the  Majes  Val- 
ley and  bordering  uplands  are  older  than  the  Pliocene  or  early 
Pleistocene  and  younger  than  the  Cretaceous  and  the  older  Ter- 
tiary lavas.  Hence  it  can  scarcely  be  doubted  that  they  represent 
a  considerable  part  of  the  Tertiary  period,  especially  in  view  of 
the  long  periods  of  accumulation  which  the  thick  sediments  rep- 
resent, and  the  additional  long  periods  represented  by  the  two 
well-marked  unconformities  between  the  three  principal  groups  of 
strata. 

If  we  now  trace  the  physical  history  of  the  region  we  have 
first  of  all  a  deep  depression  between  the  granite  range  along  the 
coast  and  the  western  flank  of  the  Andes.  Here  and  there,  as  in 
the  Vitor,  the  Majes,  and  other  valleys,  there  were  gaps  through 
the  Coast  Range.  Nowhere  did  the  relief  of  the  coastal  chain  ex- 
ceed 5,000  feet.  The  depression  had  been  partly  filled  in  early 
geologic  (probably  early  Paleozoic)  time  by  sediments  later  de- 
formed Jijid  metamorpliosed  so  Hint  llicy  are  now  quartzites  and 
shales.  The  greater  rosistauco  of  the  granite  of  the  Coast  Range 
resulted  in  superior  relief,  while  the  older  deformed  sedimentaries 
were  deeply  eroded,  with  the  result  that  by  the  beginning  of  the 
Tertiary  the  basin  quality  of  the  depression  was  again  empha- 
sized.   All  these  facts  are  expressed  graphically  in  Fig.  171.    On 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      259 

the  western  flanks  of  the  granite  range  no  corresponding  sedi- 
mentary deposits  are  found  in  this  latitude.  The  sea  thus  appears 
to  have  stood  farther  Avest  of  the  Coast  Range  in  Paleozoic  times 
than  at  present. 

For  the  later  history  it  is  necessary  to  assemble  the  various 
Tertiary  sections  described  on  the  preceding  pages.  First  of  all 
we  recognize  three  quite  distinct  types  of  accumulations,  for  which 

Coarse    alluvium    alternating   with    fine    wind- 
blown desert  deposits. 
Upper  sandstone  series. 


Lower  sandstone  series. 
Quartzites. 

Volcanic  flows. 


/S    A 


Granite-gneiss. 
Fig.   177 — Composite  structure  section  at  Aplao. 

we  shall  have  to  postulate  three  sets  of  conditions  and  possibly 
three  separate  agents.  The  first  or  lowermost  consists  of  even- 
bedded  deposits  of  red  and  gray  sandstones,  the  former  color  pre- 
dominating. The  material  is  in  general  well-sorted  save  locally, 
where  lenses  and  even  thin  beds  of  conglomerate  have  been  devel- 
oped. There  is,  however,  about  the  whole  series  a  uniformity  and 
an  orderliness  in  striking  contrast  to  the  coarse,  cross-bedded,  and 
irregular  material  above  the  unconformity.  On  their  northeast- 
ern or  inner  margin  the  sandstones  are  notably  coarser  and 
thicker,  a  natural  result  of  proximity  to  the  mountains,  the  source 
of  the  material.  The  general  absence  of  wind-blown  deposits  is 
marked;  these  occur  entirely  along  the  eastern  and  northern  por- 
tions of  the  deposits  and  are  recognized  (1)  by  their  peculiar 
cross-bedding,  and  (2)  by  the  fact  that  the  cross-bedding  is  di- 
rected northeastward  in  a  direction  contrary  to  the  regional  dip 
of  the  series,  a  condition  attributable  to  the  strong  sea  breezes 
that  prevail  every  afternoon  in  this  latitude. 

The  main  body  of  the  material  is  such  as  might  be  deposited 
on  the  wide  flood  plains  of  piedmont  streams  during  a  period  of 


260  THE  ANDES  OF  SOUTHERN  PERU 

prolonged  erosion  on  surrounding  highlands  that  served  as  the 
feeding  grounds  of  the  streams.  The  alternations  in  the  charac- 
ter of  the  deposits,  alternations  which,  in  a  general  view,  give  a 
banded  appearance  to  the  rock,  are  produced  by  successions  of 
beds  of  fine  and  coarse  material,  though  all  of  it  is  sandstone. 
Such  successions  are  probably  to  be  correlated  with  seasonal 
changes  in  the  volume  and  load  of  the  depositing  streams. 

To  gain  an  idea  of  the  conditions  of  deposition  we  may  take 
the  character  of  the  sediments  as  described  above,  and  from  them 
draw  deductions  as  to  the  agents  concerned  and  the  manner  of 
their  action. 

We  may  also  apply  to  the  area  the  conclusions  drawn  from 
the  study  of  similar  deposits  now  in  process  of  formation.  We 
have  between  the  coast  ranges  of  northern  Chile  and  the  western 
flanks  of  the  Cordillera  Sillilica,  probably  the  best  example  of 
piedmont  accumulation  in  a  dry  climate  that  the  west  coast  of 
South  America  affords. 

Along  the  inner  edge  of  the  Desert  of  Tarapaca,  roughly  be- 
tween the  towns  of  Tarapaca  and  Quillagua,  Chile,  the  piedmont 
gravels,  sands,  silts,  and  muds  extend  for  over  a  hundred  miles, 
flanking  the  western  Andes  and  forming  a  transition  belt  between 
these  mountains  and  the  interior  basins  of  the  coast  desert.  The 
silts  and  muds  constitute  the  outer  fringe  of  the  piedmont  and 
are  interrupted  here  and  there  where  sands  are  blown  upon  them 
from  the  higher  portions  of  the  piedmont,  or  from  the  desert 
mountains  and  plains  on  the  seaward  side.  Practically  no  rain 
falls  upon  the  greater  part  of  the  desert  and  the  only  water  it  re- 
ceives is  that  borne  to  it  by  the  piedmont  streams  in  the  early 
summer,  from  the  rains  and  melted  snows  of  the  high  plateau  and 
mountains  to  tlio  eastward.  Tliosc  temporary  streams  spread 
upon  the  outer  edge  of  tlie  piedmont  a  wide  sheet  of  mud  and  silt 
which  then  dries  and  becomes  cracked,  the  curled  and  warped 
plates  retaining  their  cliaractcr  until  tlie  next  wet  season  or  until 
covered  witli  wind-blown  sand.  The  wind-driven  sand  fills  the 
cracks  in  the  muds  and  is  even  drifted  under  the  edges  of  the  up- 
curled  plates,  filling  the  spaces  completely.     Over  this  combined 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      261 

fluvial  and  seolian  deposit  is  spread  the  next  layer  of  mud,  which 
frequently  is  less  extensive  than  the  earlier  deposits,  thus  giving 
abundant  opportunity  for  the  observation  of  the  exact  manner  of 
burial  of  the  older  sand-covered  stratum. 

Now  while  the  alternations  are  as  marked  in  Peru  as  in  Chile, 
it  is  noteworthy  that  the  Tertiary  material  in  Peru  is  not  only 
coarse  throughout,  even  to  the  farthest  limits  of  the  piedmont, 
but  also  that  the  alternating  beds  are  thick.  Moreover,  there  are 
only  the  most  feeble  evidences  of  wind  action  in  the  lowermost; 
Tertiary  series.  I  was  prepared  to  find  curled  plates,  wind-blowni 
sands,  and  muds  and  silts,  but  they  are  almost  wholly  absent.  ItJ 
is,  therefore,  concluded  that  the  dryness  was  far  less  extreme  thaii 
it  is  today  and  that  full  streams  of  great  competency  flowed  vigor- 
ously down  from  the  mountains  and  carried  their  loads  to  the  in- 
ner border  of  the  Coast  Range  and  in  places  to  the  sea.  ^ 

The  fact  that  the  finer  material  is  sandy,  not  clayey  or  silty, 
that  it  almost  equals  in  thickness  the  coarser  layers,  and  that  its 
distribution  appears  to  be  co-extensive  with  the  coarser,  warrants 
the  conclusion  that  it  too  was  deposited  by  competent  streams  of 
a  type  far  different  from  the  withering  streams  associated  mth 
piedmont  deposits  in  a  thoroughly  arid  climate  like  that  of  today. 
Both  in  the  second  Tertiary  series  and  on  the  present  surface  are 
such  clear  examples  of  deposits  made  in  a  drier  climate  as  to  leave 
little  doubt  that  the  earliest  of  the  Tertiary  strata  of  the  Majes 
Valley  were  deposited  in  a  time  of  far  greater  rainfall  than  the 
present.  It  is  further  concluded  that  there  was  increasing  dry- 
ness, as  shown  by  hundreds  of  feet  of  wind-blown  sand  near  the 
top  of  the  section.  But  the  growing  dryness  was  interrupted  by 
at  least  one  period  of  greater  precipitation.  Since  that  time  there 
has  been  a  return  to  the  dry  climate  of  a  former  epoch. 

Uplift  and  erosion  of  the  earliest  of  the  Tertiary  deposits  of 
the  Majes  Valley  is  indicated  in  two  ways:  (1)  by  the  deformed 
character  of  the  beds,  and  (2)  by  the  ensuing  coarse  deposits 
which  were  derived  from  the  invigorated  streams.  Without 
strong  deformations  it  would  not  be  possible  to  assign  the  in- 
creased erosion  so  confidently  to  uplift;  with  the  coarse  deposits 


262  THE  ANDES  OF  SOUTHERN  PERU 

that  succeed  the  uuconformity  we  have  evidence  of  accumulation 
under  conditions  of  renewed  uplift  in  the  mountains  and  of  full 
streams  competent  to  remove  the  increasing  load. 

It  is  in  the  character  of  the  sediments  toward  the  top  of  the 
Tertiary  that  we  have  the  clearest  evidence  of  progressive  desic- 
cation of  the  climate  of  the  region.  The  amount  of  wind-blown 
material  steadily  increases  and  the  uppermost  five  hundred  feet  is 
composed  predominantly,  and  in  places  exclusively,  of  this  ma- 
terial. The  evidences  of  wind  action  lie  chiefly  in  the  fine  (in 
places  fluffy)  nature  of  the  deposits,  their  uniform  character,  and 
in  the  tangency  of  the  layers  with  respect  to  the  surface  on  which 
they  were  deposited.  There  are  three  diagnostic  structural  fea- 
tures of  great  importance :  the  very  steep  dip  of  the  fine  laminae ; 
the  peculiar  and  harmonious  blending  of  their  contacts ;  the  man- 
ner in  which  the  highly  inclined  laminae  cut  off  and  succeed  each 
other,  whereby  quite  bewildering  changes  in  the  direction  of  dip 
of  the  inclined  beds  are  brought  about  on  any  exposed  plane. 
Some  of  these  features  require  further  discussion. 

It  is  well  known  that  the  front  of  a  sand  dune  generally  con- 
sists of  sand  deposited  on  a  slope  inclined  at  the  angle  of  repose, 
say  between  GO""  and  35°,  and  rolled  into  place  up  the  long  back 
slope  of  the  dune  by  the  wind.  It  has  not,  however,  been  gener- 
ally recognized  that  the  angle  of  repose  may  be  exceeded  (a)  when 
there  exists  a  strong  back  eddy  or  (b)  when  the  wind  blows  vio- 
lently and  for  a  short  time  in  the  opposite  direction.  In  either  case 
sand  is  carried  up  the  short  steep  slope  of  the  dune  front  and 
accumulated  at  an  angle  not  infrequently  running  up  to  43°  and 
48°- and  locally,  and  under  the  most  favorable  circumstances,  in 
excess  of  50°.  The  conditions  under  which  those  steep  angles  are 
attained  are  undoubtedly  not  universal,  but  they  can  be  found  in 
some  parts  of  almost  any  desert  in  the  world.  They  appear  not 
to  bo  present  where  the  sand  grains  are  of  uniform  size  through- 
out, since  that  leads  to  rolling.  They  are  found  rather  where  there 
is  a  certain  limited  variation  in  size  that  promotes  packing. 
T^aoking  and  tlif  flfNclnpineiii  of  sloo])  slopes  aro  also  facililatod 
ill  pnrfs  of  tlie  coastal  desert  of  Peru  by  a  cloud  canopy  that  hangs 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      263 

over  the  desert  in  the  early  morning,  that  in  the  most  favorable 
places  moistens  even  the  dune  surfaces  and  that  has  least  penetra- 
tion on  the  steep  semi-protected  dune  fronts.  Sand  later  blown 
up  the  dune  front  or  rolled  down  from  the  dune  crest  is  en- 
couraged to  remain  near  the  cornice  on  an  abnormally  steep  slope 
by  the  attraction  which  the  slightly  moister  sand  has  for  the  dry 
grains  blown  against  it.  Since  dunes  travel  and  since  their  front 
layers,  formed  on  steep  slopes,  are  cut  off  to  the  level  of  the  sur- 
face in  the  rear  of  the  dune,  it  follows  that  the  steepest  dips  in 
exposed  sections  are  almost  always  less  than  those  in  existing 
dunes.  Exceptions  to  the  rule  will  be  noted  in  filled  hollows  not 
re-excavated  until  deeply  covered  by  wind-blown  material.  These, 
re-exposed  at  the  end  of  a  long  period  of  wind  accumulation,  may 
exhibit  even  the  maximum  dips  of  the  dune  cornices.  Such  will 
be  conspicuously  the  case  in  sections  in  aggraded  desert  deposits. 
On  the  border  of  the  Majes  Valley,  from  400  to  500  feet  of  wind- 
accumulated  deposits  may  be  observed,  representing  a  long  period 
of  successive  dune  burials. 

The  peculiar  blending  of  the  contact  lines  of  dune  laminae,  re- 
lated to  the  tangency  commonly  noted  in  dune  accumulations,  is 
apparently  due  to  the  fact  that  the  wind  does  not  require  a  graded 
surface  to  work  on,  but  blows  uphill  as  well  as  down.  It  is  pres- 
ent on  both  the  back-slope  and  the  front-slope  deposits.  Its  finest 
expression  appears  to  be  in  districts  where  the  dune  material  was 
accumulated  by  a  violent  wind  whose  effects  the  less  powerful 
winds  could  not  destroy. 

It  is  to  the  ability  of  the  wind  to  transport  material  against, 
as  well  as  with,  gravity,  that  we  owe  the  third  distinct  quality  of 
dune  material,  the  succession  of  flowing  lines,  in  contrast  to  the 
succession  of  now  flat-lying  now  steeply  inclined  beds  character- 
istic of  cross-bedded  material  deposited  by  w^ater.  One  dune  trav- 
els across  the  face  of  the  country  only  to  be  succeeded  by  another.^ 
Even  if  wind  aggradation  is  in  progress,  the  plain-like  surface  in 
the  rear  of  a  dune  may  be  excavated  to  the  level  of  steeply  inclined 

"  The  best  photograph  of  tliis  condition  which  I  have  yet  seen  is  in  W.  Sievers,  Siid- 
und  Mittelamerika,  second  ed.,  1914,  Plate  15,  p.  358. 


26 Jj  THE  ANDES  OF  SOUTHERN  PERU 

beds  upon  whose  truncated  outcrop  other  inclined  beds  are  laid, 
Fig.  178.  The  contrast  to  these  conditions  in  the  case  of  aggrada- 
tion by  water  is  so  clearly  and  easily  inferred  that  space  A\ill  not 
be  taken  to  point  them  out.  It  is  also  true  as  a  corollary  to  the 
above  that  the  greater  part  of  a  body  of  wind-drifted  material 
will  consist  of  cross-bedded  layers,  and  not  a  series  of  evenly 
divided  and  alternating  flat-lying  and  cross-bedded  layers  which 
result  from  deposition  in  active  and  variable  currents  of  water. 

The  caution  must  of  course  be  observed  that  wind  action  and 
water  action  may  alternate  ii^  a  desert  region,  as  already  de- 
scribed in  Tarapaca  in  north^'fi  Chile,  so  that  the  whole  of  a  de- 
posit may  exhibit  an  alternatk,  i  of  cross-bedded  and  flat-lying  lay- 
ers ;  but  the  former  only  are  oyxe  to  wind  action,  the  latter  to  water 
action.  >v 

Finally  it  may  be  noted  f  at  the  sudden,  frequent,  and  diversi- 
fied dips  in  the  cross-beddin-  are  peculiarly  characteristic  of  wind 
action.  Although  one  sees  in  a  given  cross-section  dips  apparently 
directed  only  toward  the  le^t  or  the  right,  excavation  will  supply 
a  third  dimension  from  which  the  true  dips  may  be  either  ob- 
served or  calculated.  These  show  an  almost  infinite  variety  of 
directions  of  dip,  even  in  f  stricted  areas,  a  condition  due  to  the 
following  causes : 

(1)  the  curved  fronts  of  sand  dunes,  which  produce  dips  con- 
centric with  respect  to  a  point  and  ranging  through  180°  of  arc; 
(2)  the  irregular  character  of  sand  dunes  in  many  places,  a  con- 
dition due  in  turn  to  (a)  tlie  changeful  character  of  the  strong 
wind  (often  not  the  prevailing  wind)  to  which  the  formation  of 
the  dunes  is  due,  and  (b)  the  influence  of  the  local  topography 
upon  wind  directions  within  short  distances  or  upon  winds  of 
different  directions  in  which  a  slight  change  in  wind  direction 
is  followed  by  a  large  change  in  the  local  currents;  (3)  the  fact 
that  all  com})inations  are  possible  between  the  erosion  levels  of 
the  wind  in  successive  generations  of  dunes  blown  across  a  given 
area,  hence  any  condition  at  a  given  level  in  a  dune  may  be  com- 
bined with  amj  other  condition  of  a  succeeding  dune;  (4)  varia- 
tions in  the  sizes  of  successive  dunes  will  lead  to  further  contrasts 


PHYSIOGRAPHIC  AND  Gi:OLOGIC  DEVELOPMENT      265 


Fig.  178 — Plan  and  cross-sections  of  superimposed  sand  dunes  of  conventional 
outline.  In  the  sections,  dune  A  is  supposed  to  have  left  only  a  small 
basal  portion  to  be  covered  by  dune  B.  In  the  same  way  dune  C  has  advanced  to  cover 
both  A  and  B.  The  basal  portions  that  have  remained  are  exaggerated  vertically  in 
order  to  display  the  stratification.  It  is  obviously  not  necessary  that  the  dunes  should 
all  be  of  the  same  size  and  shape  and  advancing  in  the  same  direction  in  order  to 
have  the  tangential  relations  here  displayed.  Nor  need  the  aggrading  material  be 
derived  from  true  dunes.  The  results  would  be  the  same  in  the  case  of  sand  drifts  with 
their  associated  wind  eddies.  All  bedded  wind-blown  deposits  would  have  the  same 
general  relations.  No  two  successive  deposits,  no  matter  from  what  direction  the 
successive  drifts  or  dunes  travel,  would  exactly  correspond  in  direction  and  amount 
of  dip. 


266  THE  ANDES  OF  SOUTHERN  PERU 

not  only  in  the  scale  of  the  features  but  also  in  the  direction  and 
amount  of  the  dips. 

Finally,  we  may  note  that  a  section  of  dune  deposits  has  a  dis- 
tinctive feature  not  exhibited  by  water  deposits.  If  the  foreset 
beds  of  a  cross-bedded  water  deposit  be  exposed  in  a  plane 
parallel  to  the  strike  of  the  beds,  the  beds  will  appear  to  be  hori- 
zontal. They  could  not  then  be  distinguished  from  the  truly 
horizontal  beds  above  and  below  them.  But  the  conditions  of  mnd 
deposition  we  have  just  noted,  and  chiefly  the  facts  expressed  by 
Fig.  178,  make  it  impossible  to  select  a  position  in  which  both 
tangency  and  irregular  dips  are  not  well  developed  in  a  wind  de- 
posit. I  believe  that  we  have  in  the  foregoing  facts  and  inferences 
a  means  for  the  definite  separation  of  these  two  classes  of  de- 
posits. Difficulties  will  arise  only  when  there  is  a  quick  succession 
of  wind  and  water  action  in  time,  or  where  the  wind  produces 
powerful  and  persistent  effects  without  the  actual  formation  of 
dunes. 

The  latest  known  deposits  in  the  coastal  region  are  found  sur- 
mounting the  terrace  tops  along  the  coast  between  Camana  and 
Quilca,  where  they  form  deposits  several  hundred  feet  thick  in 
places.  The  age  of  these  deposits  is  determined  by  fossil  evidence, 
and  is  of  extraordinary  interest  in  the  determination  of  the  age  of 
the  great  terraces  upon  which  they  lie.  They  consist  of  alternating 
beds  of  coarse  and  fine  material,  the  coarser  increasing  in  thick- 
ness and  frequency  toward  the  bottom  of  the  section.  It  is  also 
near  the  bottom  of  the  section  that  fossils  are  now  found;  the 
higher  members  are  locally  saline  and  tliroughout  tliore  is  a 
marked  inclination  of  the  beds  toward  the  present  shore.  The  de- 
posits appear  not  to  have  been  derived  from  tlie  underlying  gran- 
ite-gneiss. They  are  distributed  most  abundantly  near  the  mouths 
of  tlic  larger  streams,  as  noiiv  llic  X'ilor  at  <^|iiilcn,  and  Ihc  Majes 
at  (  ;nii;iii;'i.  Flscwlicic  tlic  Icnace  summit  is  swept  clean  of 
waste,  except  where  local  clay  d('])osits  lie  in  the  ravines,  as  back 
of  ^follendo  and  wlioro  'Miorrns  blancas"  liaxe  l)eon  accumulated 
by  the  wind. 

These  coastal  deposits  were  laid  down  upon  a  dissected  tor- 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      267 

race  up  to  five  miles  in  width.  The  degree  of  dissection  is  varia- 
ble, and  depends  upon  the  relation  of  the  through-flowing  streams 
to  the  Coast  Range.  The  Vitor  and  the  Majes  have  cut  down 
through  the  Coast  Range,  and  locally  removed  the  terrace ;  smaller 
streams  rising  on  the  flanks  of  the  Coast  Range  either  die  out 
near  the  foot  of  the  range  or  cross  it  in  deep  and  narrow  valleys. 
The  present  drainage  on  the  seaward  slopes  of  the  Coast  Range 
is  entirely  ineffective  in  reaching  the  sea,  as  was  seen  in  1911,  the 
wettest  season  know^n  on  the  coast  in  years  and  one  of  the  wettest 
probably  ever  observed  on  this  coast  by  man. 

In  consequence  of  their  deposition  on  a  terrace  that  ranges  in 
elevation  from  zero  to  1,500  feet  above  sea  level,  the  deposits  of 
the  coast  are  very  irregularly  disposed.  But  in  consequence  of 
their  great  bulk  they  have  a  rather  smooth  upper  surface,  grada- 
tion having  been  carried  to  the  point  where  the  irreg-ularities  of 
the  dissected  terrace  were  smoothed  out.  Their  general  uniform- 
ity is  broken  where  streams  cross  them,  or  where  streams  crossed 
them  during  the  wetter  Pleistocene.  Their  elevation,  several  hun- 
dred feet  above  sea  level,  is  responsible  for  the  deep  dissection 
of  their  coastal  margin,  where  great  cliffs  have  been  cut. 

PLEISTOCENE 

The  broad  regional  uplift  of  the  Permdan  Andes  in  late  Ter- 
tiary and  in  Pleistocene  times  carried  their  sunnnits  above  the! 
level  of  perpetual  snow.    It  is  still  an  open  question  whether  or  not) 
uplift  was  sufficiently  great  in  the  early  Pleistocene  to  be  in- 
fluenced by  the  first  glaciations  of  that  period.    As  yet,  there  arei' 
evidences  of  only  two  glacial  invasions,  and  both  are  considered 
late  events  on  account  of  the  freshness  of  their  deposits  and  th^ 
related  topographic  forms.    The  coarse  deposits — nearly  500  feet 
thick — that  form  the  top  of  the  desert  section  described  above 
clearly   indicate    a    wetter    climate    than    prevailed    during    the( 
deposition  of  the  several  hundred  feet  of  wind-blown  deposits  be- 
neath them.    But  if  our  interpretation  be  correct  these  deposits 
are  of  late  Tertiary  age,  and  their  character  and  position  arey 
taken  to  indicate  climatic  changes  in  the  Tertiary,     They  may 


268  THE  ANDES  OF  SOUTHERN  PERU 

have  been  the  mild  precursors  of  the  greater  climatic  changes  of 
glacial  times.  Certain  it  is  that  they  are  quite  unlike  the  mass 
of  the  Tertiary  deposits.  On  the  other  hand  they  are  separated 
from  the  deposits  of  known  glacial  age  "by  a  time  interval  of  great 
length — an  epoch  in  which  was  cut  a  benched  canyon  nearly  a  mile 
deep  and  three  miles  wide.  They  must,  therefore,  have  been 
formed  when  the  Andes  were  thousands  of  feet  lower  and  unable 
to  nourish  glaciers.  It  was  only  after  the  succeeding  uplifts  had 
raised  the  mountain  crests  well  above  the  frost  line  that  the  rec- 
ords of  oscillating  climates  were  left  in  erratic  deposits,  troughed 
valleys,  cliffed  cirques  and  pinnacled  divides. 

The  glacial  forms  are  chiefly  at  the  top  of  the  country;  the 
glacial  deposits  are  chiefly  in  the  deep  valleys  that  were  carved 
before  the  colder  climate  set  in.  The  rock  waste  ground  up  by 
the  ice  was  only  a  small  part  of  that  delivered  to  the  streams  in 
glacial  times.  Every^vhere  the  wetter  climate  resulted  in  the 
partial  stripping  of  the  residual  soil  gathered  upon  the  smooth 
mature  slopes  formed  during  the  long  Tertiary  cycle  of  erosion. 
This  moving  sheet  of  waste  as  well  as  the  rock  fragments  carried 
away  from  the  glacier  ends  were  stre\\Ti  along  the  valley  floors, 
forming  a  deep  alluvial  fill.  Thereby  the  canyon  floors  were  ren- 
dered habitable. 

In  the  chapters  on  human  geography  we  have  already  called 
attention  to  the  importance  of  the  U-shaped  valleys  carved  by  the 
glaciers.  Their  floors  are  broad  and  relatively  smooth.  Their 
walls  restrain  the  live  stock.  They  are  sheltered  though  lofty. 
But  all  the  human  benefits  conferred  by  ice  action  are  insig- 
nificant beside  those  due  to  the  general  shedding  of  waste  from 
the  cold  upper  surfaces  to  the  warm  levels  of  the  valley  floors. 
The  alluvium-filled  valleys  are  the  seats  of  dense  populations.  In 
the  lowest  of  them  tropical  and  sub-tropical  products  are  raised, 
like  sugar-cane  and  cotton,  in  a  soil  lliat  once  lay  on  the  smooth 
upper  slopes  of  mountain  spurs  or  ilint  wns  ground  fmo  on  tlic  bed 
of  an  Alpine  glacier. 

The  Pleistocene  deposits  fjill  into  three  well-defined  groups: 
(1)  glacial  accumulations  at  the  valley  heads,  (2)  alluvial  deposits 


Fig.  179 — Snow  fields  on  the  summit  of  the  Cordillera  Vilcapanipa  near  Ollantay- 
tambo.  A  huge  glacier  once  lay  in  the  steep  canyon  in  the  background  and  descended 
to  the  notched  terminal  moraine  at  the  canyon  mouth.  In  places  the  glacier  was 
over  a  thousand  feet  thick.  From  the  terminal  moraine  an  enormous  alluvial  fan  extends 
forward  to  the  camera  and  to  the  opposite  wall  of  the  Urubamba  Valley.  It  is' 
confluent  with  other  fans  of  the  same  origin.  See  Fig.  180.  In  the  foreground  are 
flowers,  shrubs,  and  cacti.     A  few  miles  below  Urubamba  at  11,500  feet. 


Fig.  180. 


I'm;     isl. 

Fifj  ISO  — Iriitcimba  \'allcy  hctwciii  OIlaiitiiN  laiiiho  ami  'I'lH-diiloy.  slidwiiif,'  (1) 
inori'  iniidiratc  up|)cr  hIouch  aiul  Hlropcr  hiwor  h1i»|)('h  of  llic  tun  cycle  iniiiiiilaiii  spins; 
(2)  till-  cxtciiMive  iilluviiil  dcpoHits  of  tho  valley,  coiirtiHtiiig  cliiclly  of  <i)iilliicii(  alluvial 
fans  h(>arlin)(  in  flie  ^lariated  muunlains  on  tlie  left.     See  Ki{^.  17It. 

Flo  IHI— (;i(iciiil  features  of  the  Cctilral  HangcH  (see  Fig.  '204).  IIu{,'c  lateral 
morainf's  built  by  ice  streams  triltutary  to  tlic  main  valley  north  of  ( 'Imipiiljiunbilla. 
That  the  tributaries  persisted  lon((  afU-r  tlie  main  valley  beoame  free  of  ice  is  shown 
by  tlie  descent  of  the  lateral  moraines  over  the  steep  border  of  the  main  valley  and 
down  to  the  Moor  of  it. 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      269 

in  the  valleys,  and  (3)  lacustrine  deposits  formed  on  the  floors  of 
temporary  lakes  in  inclosed  basins.  Among  these  the  most  varia- 
ble in  form  and  composition  are  the  true  glacier-laid  deposits  at 
the  valley  heads.  The  most  extensive  are  the  fluvial  deposits  ac- 
cumulated as  valley  fill  throughout  the  entire  Andean  realm. 
Though  important  enough  in  some  respects  the  lacustrine  deposits 
are  of  small  extent  and  of  rather  local  significance.  Practically 
none  of  them  fall  within  the  field  of  the  present  expedition ;  hence 
we  shall  describe  only  the  first  two  classes. 

The  most  important  glacial  deposits  were  accumulated  in  the 
eastern  part  of  the  Andes  as  a  result  of  greater  precipitation,  a 
lower  snow^line,  and  catchment  basins  of  larger  area.  In  the 
Cordillera  Vilcapampa  glaciers  once  existed  up  to  twelve  and  fif- 
teen miles  in  length,  and  those  several  miles  long  w^ere  numerous 
both  here  and  throughout  the  higher  portions  of  the  entire  Cordil- 
lera, save  in  the  belt  of  most  intense  volcanic  action,  which  coin- 
cides with  the  driest  part  of  the  Andes,  where  the  glaciers  were 
either  very  short  or  wanting  altogether. 

Since  vigorous  glacial  action  results  in  general  in  the  cleaning 
out  of  the  valley  heads,  no  deposits  of  consequence  occur  in  these 
locations.  Down  valley,  however,  glacial  deposits  occur  in  the 
form  of  terminal  moraines  of  recession  and  ground  moraines. 
The  general  nature  of  these  deposits  is  now  so  well  known  that 
detailed  description  seems  quite  unnecessary  except  in  the  case 
of  unusual  features. 

It  is  noteworthy  that  the  moraines  decrease  in  size  up  valley 
since  each  valley  had  been  largely  cleaned  out  by  ice  action  before 
the  retreat  of  the  glacier  began.  Each  lowermost  terminal 
moraine  is  fronted  by  a  great  mass  of  unsorted  coarse  bowldery 
material  forming  a  fill  in  places  several  hundred  feet  thick,  as  be- 
low Choquetira  and  in  the  Vilcapampa  Valley  between  Vilca- 
bamba  and  Puquiura.  This  bowldery  fill  is  quite  distinct  from  the 
long,  gently  inclined,  and  stratified  valley  train  below  it,  or  the 
marked  ridge-like  moraine  above  it.  It  is  in  places  a  good  half 
mile  in  length.  Its  origin  is  believed  to  be  due  to  an  overriding 
action  beyond  the  last  terminal  moraine  at  a  time  when  the  ice 


270  THE  ANDES  OF  SOUTHERN  PERU 

was  well  charged  with  debris,  an  overriding  not  marked  by 
morainal  accumulations,  chiefly  because  the  ice  did  not  maintain 
an  extreme  position  for  a  long  period. 

In  the  vicinity  of  the  terminal  moraines  the  alluvial  valley  fill 
is  often  so  coarse  and  so  unorganized  as  to  look  like  till  in  the  cut 
banks  along  the  streams,  though  its  alluvial  origin  is  always 
shown  by  the  topographic  form.  This  characteristic  is  of  special 
geologic  interest  since  the  form  may  be  concealed  through  deposi- 
tion or  destroyed  by  erosion,  and  no  condition  but  the  structure 
remain  to  indicate  the  manner  of  origin  of  the  deposit.  In  such 
an  event  it  would  not  be  possible  to  distinguish  between  alluvium 
and  till.  The  gravity  of  the  distinction  appears  when  it  is  known 
that  such  apparently  unsorted  alluvium  may  extend  for  several 
miles  forward  of  a  terminal  moraine,  in  the  shape  of  a  wide- 
spreading  alluvial  fan  apparently  formed  under  conditions  of  ex- 
tremely rapid  aggradation.  I  suppose  it  would  not  be  doubted  in 
general  that  a  section  of  such  stony,  bowldery,  unsorted  material 
two  miles  long  would  have  other  than  a  glacial  origin,  yet  such 
may  be  the  case.  Indeed,  if,  as  in  the  Urubamba  Valley,  a  future 
section  should  run  parallel  to  the  valley  across  the  heads  of  a 
great  series  of  fans  of  similar  composition,  topographic  form,  and 
origin,  it  would  be  possible  to  see  many  miles  of  such  material. 

The  depth  of  the  alluvial  valley  fill  due  to  tributary  fan  ac- 
cumulation depends  upon  both  the  amount  of  the  material  and  the 
form  of  the  valley.  Below  Urubamba  in  the  Urubamba  Valley  a 
fine  series  is  displayed,  as  shown  in  Fig.  180.  The  fans  head  in 
valleys  extending  up  to  snow-covered  summits  upon  whose  flanks 
living  glaciers  are  at  work  today.  Their  heads  are  now  crowned 
by  terminal  moraines  and  both  moraines  and  alluvial  fans  are  in 
process  of  dissection.  'I'he  height  and  extent  of  the  moraines  and 
the  alluvial  fans  are  in  rough  proportion  and  in  turn  reflect  the 
lieight,  elevation,  and  extent  of  the  valley  heads  which  served  as 
fields  of  nourishment  for  the  Pleistocene  glaciers.  Where  the  fans 
were  deposited  in  narrow  valleys  the  effect  was  to  increase  the 
thickness  of  the  deposits  at  the  expense  of  their  area,  to  dam  the 
drainage  lines  or  displace  them,  and  to  so  load  the  streams  that 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      271 


they  have  not  yet  cleared  their  beds  after  thousands  of  years  of 
work  under  torrential  conditions. 

Below  Urubamba  the  alluvial  fans  entering  the  main  valley 
from  the  east  have  pushed  the  river  against  its  western  valley 
wall,  so  that  the  river  flows  on  one  side  against  rock  and  on  the 
other  against  a  hundred  feet  of  stratified  material.  In  places,  as 
at  the  head  of  the  narrows  on  the  valley  trail  to  Ollantaytambo, 
a  flood  plain  has  been  formed  in  front  of  the  scarp  cut  into  the 
alluvium,  while  the  edge  of  the  dissected  alluvial  fans  has  been 
sculptured  into  erosion  forms  resembling  bad-lands  topography. 
On  the  western  side  of  the  valley  the  alluvial  fans  are  very  small, 
since  they  are  due  to  purely  local  accumulations  of  waste  from 
the  edge  of  the  plateau.  Glaciation  has  here  displaced  the  river. 
Its  effects  will  long  be  felt  in  the  disproportionate  erosion  of  the 
western  wall  of  the  valley. 

By  far  the  most  interesting  of  the  deposits  of  glacial  time  are  \ 
those  laid  down  on  the  valley  floors  in  the  form  of  an  alluvial  fill. 

Though  such  deposits  have 

greater  thickness  as  a  rule 
near  the  nourishing  mo- 
raines or  bordering  allu- 
vial fans  at  the  lower  ends 
of  the  valleys,  they  are 
everywhere  important  in 
amount,  distinctive  in  topo- 
graphic form,  and  of  amaz- 
ingly wide  extent.  They 
reach  far  into  and  possibly 
across  the  Amazon  basin, 
they  form  a  distinct  though 
small  piedmont  fringe  along  the  eastern  base  of  the  Andes,  and 
they  are  universal  throughout  the  Andean  valleys.  That  a  deposit 
of  such  volume — many  times  greater  than  all  the  material  accumu- 
lated in  the  form  of  high-level  alluvial  fans  or  terminal  moraines 
— should  originate  in  a  tropical  land  in  a  region  that  suffered  but 
limited  Alpine  glaciation  vastly  increases  its  importance. 


...■.J!;:iW<''':!mm^::m 


Fig.  182 — Dissected  alluvial  fans  on  the 
border  of  the  Urubamba  Valley  near  Hacienda 
Chinche.  A  characteristic  feature  of  the 
valleys  of  the  Peruvian  Andes  below  the  zone 
of  glaciation  but  within  the  limits  of  its  ag- 
graditional  effects.  Through  alluviation  the 
valleys  and  basins  of  the  Andean  Cordillera, 
and  vast  areas  of  the  great  Amazon  plains  east 
of  it,  felt  the  effects  of  the  glacial  conditions 
of  a  past  age. 


272 


THE  ANDES  OF  SOUTHERN  PERU 


■■•'-"-v;-;'--vAiifvriLL 


The  fill  is  composed  of  both  fine  and  coarse  material  laid  do^^^l 
by  water  in  steep  valley  floors  to  a  depth  of  many  feet.  It  breaks 
the  steep  slope  of  each  valley,  forming  terraces  with  pronounced 
frontal  scarps  facing  the  river.  On  the  raw  bluffs  at  the  scarps 
made  by  the  encroaching  stream  good  exposures  are  afforded. 
At  Chinche  in  the  Urubamba  Valley  above  Santa  Ana,  the  material 
is  both  sand  and  clay  with  an  important  amount  of  gravel  laid 
down  with  steep  valleyward  inclination  and  under  torrential  con- 
ditions; so  that  mthin  a 
given  bed  there  may  be  an 
apparent  absence  of  lamina- 
tion. Almost  identical  con- 
ditions are  exhibited  fre- 
quently along  the  railway  to 
Cuzco  in  the  Vilcanota  Val- 
ley. The  material  is  mixed 
sand  and  gravel,  here  and 
there  running  to  a  bowldery 
or  stony  mass  where  acces- 
sions have  been  received 
from  some  source  nearby. 
It  is  modified  along  its  mar- 
gin not  only  in  topographic 
form  but  also  in  composition 
by  small  tributary  alluvial 
fans,  though  those  in  general 
constitute  but  a  small  part  of  the  total  mass.  At  Cotahuasi,  Fig. 
29,  there  is  a  remarkable  fill  at  least  four  hundred  feet  deep  in 
many  pljicos  whore  the  river  has  exposed  fine  sections.  The 
(Icplli  of  the  fill  is,  li()\vc\('i-,  not  determined  by  tlio  lioiglit  of  llie 
erosion  bluffs  cut  into  it,  since  the  bed  of  the  river  is  made  of  the 
same  material.  I'lie  rock  floor  of  the  valley  is  probably  at  least 
an  additional  hundred  feet  below  the  present  level  of  the  river. 

Similar  conditions  are  well  displayed  at  ITuadquina,  where  a 
fine  series  of  terraces  at  tlio  lower  end  of  llic  Torontoy  Canyon 
break  the  descent  of  llu'  environing  slopes;  also  in  the  Urubamba 


l"i(,.  is:; — 'rwo-ryclc  slopes  aiul  alluvial  lill 
between  lluichiliuu  and  CluKiuibainbilla.  The 
steep  slopes  on  the  inner  valley  border  are  in 
many  places  vertical  and  rock  cliflfs  are  every- 
where abundant.  ^Mature  slopes  have  their 
greatest  development  here  betAveen  13,500  and 
15,000  feet  (4,110  to  4,570  m.).  Steepest  ma- 
ture slopes  run  from  15°  to  21°.  Least  steep 
are  the  almost  level  spur  summits.  The  depths 
of  the  valley  fill  must  be  at  least  300,  and  may 
possibly  be  500  feet.  The  break  between  valley 
fill  and  steep  slopes  is  most  pronounced  where 
the  river  runs  along  the  valley  wall  or  under- 
cuts it;  hast  pronounced  where  alluvial  fans 
spread  out  from  the  head  of  some  ravine.  It 
is  a  bowldery,  stony  fill  almost  everywhere 
terraced  and  cultivated. 


PHYSIOGRAPHIC  AND  GEOLOGIC  DEVELOPMENT      273 

Valley  below  Rosalina,  and  again  at  the  edge  of  the  mountains  at 
the  Pongo  de  Mainique.    It  is  exhibited  most  impressively  in  the 
Majes  Valley,  where  the  bordering  slopes  appear  to  be  buried  / 
knee-deep  in  waste,  and  where  from  any  reasonable  downward  ex-  / 
tension  of  rock  walls  of  the  valley  there  would  appear  to  be  at/ 
least  a  half  mile  of  it.    It  is  doubtful  and  indeed  improbable  that/ 
the  entire  fill  of  the  Majes  Valley  is  glacial,  for  during  the  Pliocene 
or  early  Pleistocene  there  was  a  submergence  which  gave  op- 
portunity for  the  partial  filling  of  the  valley  wdth  non-glacial  al- 
luvium, upon  which  the  glacial  deposits  were  laid  as  upon  a  flat 
and  extensive  floor  that  gives  an  exaggerated  impression  of  their 
depth.    However,  the  head  of  the  Majes  Valley  contains  at  least 
six  hundred  feet  and  probably  as  much  as  eight  hundred  feet  of 
alluvium   now   in   process    of   dissection,   whose    coarse    texture 
and  position  indicates  an  origin  under  glacial  conditions.     The 
fact  argues  for  the  great  thickness  of  the  alluvial  material  of  the 
lower  valley,  even  granting  a  floor  of  Pliocene  or  early  Pleistocene  I 
sediments.     The  best  sections  are  to  be  found  just  below^  Chu- 
quibamba  and  again  about  halfway  between  that  city  and  Aplao,  I 
whereas  the  best  display  of  the  still  even-floored  parts  of  the 
valley  are  between  Aplao  and  Cantas,  where  the  braided  river 
still  deposits  coarse  gravels  upon  its  wide  flood  plain. 


CHAPTEE  XVI 
GLACIAL  FEATURES 

THE   SNOWLINE 

South  America  is  classical  ground  in  the  study  of  tropical 
snowlines.  The  African  mountains  that  reach  above  the  snowline 
in  the  equatorial  belt — Ruw^enzori,  Kibo,  and  Kenia — have  only- 
been  studied  recently  because  they  are  remote  from  the  sea  and 
surrounded  by  bamboo  jungle  and  heavy  tropical  forest.  On  the 
other  hand,  many  of  the  tropical  mountains  of  South  America  lie 
so  near  the  west  coast  as  to  be  visible  from  it  and  have  been 
studied  for  over  a  hundred  years.  From  the  days  of  Humboldt 
(1800)  and  Boussingault  (1825)  down  to  the  present,  observations 
in  the  Andes  have  been  made  by  an  increasing  number  of  scientific 
travelers.  The  result  is  a  large  body  of  data  upon  which  compara- 
tive studies  may  now  be  profitably  undertaken. 

Like  scattered  geographic  observations  of  many  other  kinds, 
the  earlier  studies  on  the  snowline  have  increased  in  value  with 
time,  because  the  snowline  is  a  function  of  climatic  elements  that 
are  subject  to  periodic  changes  in  intensity  and  cannot  be  under- 
stood by  reference  to  a  single  observation.  Siiice  the  discovery 
of  physical  proofs  of  climatic  changes  in  short  cycles,  studies 
have  been  made  to  determine  the  direction  and  rate  of  change  of 
the  snowline  the  world  over,  with  some  very  striking  results. 

It  has  been  found  ^  that  the  changes  run  in  cycles  of  from 
thirty  to  thirty-five  years  in  length  and  that  the  northern  and 
southern  hemispheres  appear  to  be  in  opposite  phase.  For  ex- 
ample, since  1885  the  snowline  in  the  southern  hemisphere  has 
been  decreasing  in  elevation  in  nine  out  of  twelve  cases  by  the 
average  amount  of  nine  hundred  feet.    With  but  a  single  excep- 


'  Pnflchingor,     Die     Pchnooprrnzf'      in      vrrsphicfloncn      Klimnton.       Peter.       ISIilt. 
Erganz'l.cft,  Nr.   173.   1912,  pp.  020.'!. 

274 


GLACIAL  FEATURES  275 

tion,  tlie  snowline  in  the  northern  hemisphere  has  been  rising 
since  1890  with  an  average  increase  of  five  hundred  feet  in  sixteen 
cases.  To  be  sure,  we  must  recognize  that  the  observations  upon 
which  these  conclusions  rest  have  unequal  value,  due  both  to  per- 
sonal factors  and  to  differences  in  instrumental  methods,  but  that 
in  spite  of  these  tendencies  toward  inequality  they  should  agree 
in  establishing  a  general  rise  of  the  snowline  in  the  northern 
hemisphere  and  an  opposite  effect  in  the  southern  is  of  the  high- 
est significance. 

It  must  also  be  realized  that  snowline  observations  are  alto- 
gether too  meager  and  scattered  in  view  of  the  abundant  op- 
portunities for  making  them,  that  they  should  be  standardized, 
and  that  they  must  extend  over  a  much  longer  period  before  they 
attain  their  full  value  in  problems  in  climatic  variations.  Once 
the  possible  significance  of  snowline  changes  is  appreciated  the 
number  and  accuracy  of  observations  on  the  elevation  and  local 
climatic  relations  of  the  snowline  should  rapidly  increase. 

In  1907  I  made  a  number  of  observations  on  the  height  of  the 
snow^line  in  the  Bolivian  and  Chilean  Andes  betw^een  latitudes  17° 
and  20°  south,  and  in  1911  extended  the  w^ork  northward  into  the 
Peruvian  Andes  along  the  seventy-third  meridian.  It  is  proposed 
here  to  assemble  these  observations  and,  upon  comparison  wdth 
published  data,  to  make  a  few  interpretations. 

From  Central  Lagunas,  Chile,  I  went  northeastward  via  Pica 
and  the  Huasco  Basin  to  Llica,  Bolivia,  crossing  the  Sillilica  Pass 
in  May,  1907,  at  15,750  feet  (4,800  m.).  Perpetual  snow  lay  at  an 
estimated  height  of  2,000-2,500  feet  above  the  pass  or  18,000  feet 
(5,490  m.)  above  the  sea.  Two  weeks  later  the  Huasco  Basin, 
14,050  feet  (4,280  m.),  w^as  covered  a  half -foot  deep  with  snow  and 
a  continuous  snow  mantle  extended  do^\Ti  to  13,000  feet.  Light 
snows  are  reported  from  12,000  feet,  but  they  remain  a  few^  hours 
only  and  are  restricted  to  the  height  of  exceptionally  severe  win- 
ter seasons  (June  and  early  July).  Three  or  four  distant  snow- 
capped peaks  were  observed  and  estimates  made  of  the  elevation 
of  the  snowline  between  the  Cordillera  Sillilica  and  Llica  on  the 
eastern   border   of   the   Maritime    Cordillera.     All   observations 


276  THE  ANDES  OF  SOUTHERN  PERU 

agreed  in  gning  au  elevation  mucli  in  excess  of  17,000  feet.  In 
general  the  values  run  from  18,000  to  19,000  feet  (5,490  to  5,790 
m.).  Though  the  bases  of  these  figures  are  estimates,  it  should 
be  noted  that  a  large  part  of  the  trail  lies  between  14,000  and 
16,000  feet,  passing  mountains  snow-free  at  least  2,000  to  3,000 
feet  higher,  and  that  for  general  comparisons  they  have  a  distinct 
value. 

In  the  Eastern  Cordillera  of  Boli\da,  snow  was  observed  on 
the  summit  of  the  Tunari  group  of  peaks  northwest  of  Cocha- 
bamba.  Steinmann,  who  visited  the  region  in  1904,  but  did  not 
reach  the  summit  of  the  Tunari  group  of  peaks,  concludes  that 
the  limit  of  perpetual  snow  should  be  placed  above  the  highest 
point,  17,300  (5,270  m.) ;  but  in  July  and  August,  1907,  I  saw  a 
rather  extensive  snow  cover  over  at  least  the  upper  1,000  feet,  and 
what  appeared  to  be  a  very  small  glacier.  Certain  it  is  that  the 
Cochabamba  Indians  bring  clear  blue  ice  from  the  Tunari  to  the 
principal  hotels,  just  as  ice  is  brought  to  Cliza  from  the  peaks 
above  Arani.  On  these  grounds  I  am  inclined  to  place  the  snow- 
line at  17,000  feet  (5,180  m.)  near  the  eastern  border  of  the 
Eastern  Cordillera,  latitude  17°  S.  At  13,000  feet,  in  July,  1907, 
snow  occurred  in  patches  only  on  the  pass  called  Abre  de  Malaga, 
northeast  of  Colomi,  13,000  feet,  and  fell  thickly  while  we  were 
descending  the  northern  slopes  toward  Corral,  so  that  in  the  early 
morning  it  extended  to  the  cold  timber  line  at  10,000  feet.  In  a 
few  hours,  however,  it  had  vanished  from  all  but  the  higher  and 
the  shadier  situations. 

In  the  Vilcanota  knot  above  the  divide  between  the  Titicaca 
and  Vilcanota  hydrographic  systems,  the  elevation  of  the  snow- 
line was  16,300-f  feet  (4,970  m.)  in  September,  1907.  On  the 
Cordillera  Real  of  Bolivia  it  is  17,000  to  17,500  feet  on  the  north- 
east, but  falls  to  10,000  feet  on  the  southwest  above  La  Paz.  In 
the  first  week  of  July,  1911,  snow  fell  on  the  streets  of  Cuzco 
(11,000  feet)  and  remained  for  over  an  hour.  The  heights  north 
of  San  Gcronimo  (16,000  feet)  miss  the  limit  of  perpetual  snow 
and  jirc  snow-covered  only  a  few  months  each  year. 

In  taking  observations  on  the  snowline  along  the  seventy-third 


GLACIAL  FEATURES  277 

meridian  I  was  fortunate  enough  to  have  a  topographer  the 
heights  of  whose  stations  enabled  me  to  correct  the  readings  of 
my  aneroid  barometer  whenever  these  were  taken  off  the  line  of 
traverse.  Furthermore,  the  greater  height  of  the  passes — 15,000 
to  17,600  feet — brought  me  more  frequently  above  the  snowline 
than  had  been  the  case  in  Bolivia  and  Chile.  More  detailed  ob- 
servations were  made,  therefore,  not  only  upon  the  elevation  of 
the  snowline  from  range  to  range,  but  also  upon  the  degree  of 
canting  of  the  snowline  on  a  given  range.  Studies  were  also  made 
on  the  effect  of  the  outline  of  the  valleys  upon  the  extent  of  the 
glaciers,  the  influence  on  the  position  of  the  snowline  of  mass  ele- 
vation, precipitation,  and  cloudiness. 

Snow  first  appears  at  14,500  feet  (4,320  m.)  on  the  eastern 
flanlvs  of  the  Cordillera  Vilcapampa,  in  13°  south  latitude.  East 
of  this  group  of  ridges  and  peaks  as  far  as  the  extreme  eastern 
border  of  the  mountain  belt,  fifty  miles  distant,  the  elevations 
decrease  rapidly  to  10,000  feet  and  lower,  with  snow  remaining 
on  exceptionally  high  peaks  from  a  few  hours  to  a  few  months. 
In  the  winter  season  snow  falls  now  and  then  as  low  as  11,500  feet, 
as  in  the  valley  below  Vilcabamba  pueblo  in  early  September, 
1911,  though  it  vanishes  like  mist  with  the  appearance  of  the  sun 
or  the  warm  up-valley  winds  from  the  forest.  Storms  gather 
daily  about  the  mountain  summits  and  replenish  the  perpetual 
snow  above  15,000  feet.  In  the  first  pass  above  Puquiura  we  en- 
countered heavy  snow  banks  on  the  northeastern  side  a  hundred 
feet  below  the  pass  (14,500  feet),  but  on  the  southwestern  or  lee- 
ward side  it  is  five  hundred  feet  lower.  This  distribution  is  ex- 
plained by  the  lesser  insolation  on  the  southwestern  side,  the  im- 
mediate drifting  of  the  clouds  from  the  windward  to  the  leeward 
slopes,  and  to  the  mutual  intensification  of  cause  and  effect  h^ 
topographic  changes  such  as  the  extension  of  collecting  basins  and 
the  steeping  of  the  slopes  overlooking  them  ^\ith  a  correspond- 
ing increase  in  the  duration  of  shade. 

It  is  well  known  that  with  increase  of  elevation  and  there- 
fore of  the  rarity  of  the  air  there  is  less  absorption  of  the  sun's 
radiant  energy,  and  a  corresponding  increase  in  the  degree  of  in- 


278  THE  ANDES  OF  SOUTHERN  PERU 

solation.  It  follows,  therefore,  that  at  high  altitudes  the  contrasts 
between  sun  and  shade  temperatures  will  increase.  Frankland ' 
has  showTi  that  the  increase  may  run  as  high  as  500  per  cent  be- 
tween 100  to  10,000  feet  above  the  sea.  I  have  noted  a  fall  of  tem- 
perature of  15°  F.  in  six  minutes,  due  to  the  obscuring  of  the  sun 
by  cloud  at  an  elevation  of  16,000  feet  above  Huichihua  in  the 
Central  Ranges  of  Peru.  Since  the  sun  shines  approximately 
half  the  time  in  the  snow-covered  portions  of  the  mountains  and 
since  the  tropical  Andes  are  of  necessity  snow-covered  only  at 
lofty  elevations,  this  contrast  between  shade  and  sun  tempera- 
tures is  by  far  the  most  powerful  factor  influencing  differences  in 
elevation  of  the  snowline  in  Peru. 

To  the  drifting  of  the  fallen  snow  is  commonly  ascribed  a 
large  portion  of  this  contrast.  I  have  yet  to  see  any  evidence  of 
its  action  near  the  snowline,  though  I  have  often  observed  it, 
especially  under  a  high  wind  in  the  early  morning  hours  at  con- 
siderable elevations  above  the  snowline,  as  at  the  summits  of  lofty 
peaks.  It  appears  that  the  lower  ranges  bearing  but  a  limited 
amount  of  snow  are  not  subject  to  drifting  because  of  the  wetness 
of  the  snow,  and  the  fact  that  it  is  compacted  by  occasional  rains 
and  hail  storms.  Only  the  drier  snow  at  higher  elevations  and 
under  stronger  winds  can  be  effectively  dislodged. 

The  effect  of  unequal  distribution  of  precipitation  on  the  wind- 
ward and  leeward  slopes  of  a  mountain  range  is  in  general  to  de- 
press the  snowline  on  the  windward  slopes  where  the  greater 
amount  falls,  but  this  may  be  offset  in  high  altitudes  by  tempera- 
ture contrasts  as  in  the  westward  trending  Cordillera  Vilcapampa, 
where  north  and  south  slopes  are  in  opposition.  If  the  Cordillera 
Vilcapampa  ran  north  and  south  we  should  have  the  windward 
and  leeward  slopes  equally  exposed  to  the  sun  and  the  snowline 
would  lie  at  a  lower  elevation  on  the  eastern  side.  Among  all  the 
Iranges  the  slopes  have  decreasing  precipitation  to  the  leeward, 
that  is,  westerly.  The  second  and  third  passes,  between  Arma  and 
Choquetira,  are  snow-free  (though  their  elevations  equal  those  of 

'  Ilnnn,  Handbook  of  Climatology,  Part  1,  trans,  hy  Ward,  lOO.*],  p.  232. 


GLACIAL  FEATURES  279 

the  first  pass)  because  they  are  to  leeward  of  the  border  range, 
hence  receive  less  precipitation.  The  depressive  effect  of  increased 
precipitation  on  the  snowline  is  represented  by  A-B,  Fig.  184 ;  in 
an  individual  range  the  effect  of  heavier  precipitation  may  be  off- 
set by  temperature  contrasts  between  shady  and  sunny  slopes,  as 
shown  by  the  line  a-b  in  the  same  figure. 

The  degree  of  canting  of  the  snowline  on  opposite  slopes  of 
the  Cordillera  Vilcapampa  varies  between  5°  and  12°,  the  higher 
value  being  represented  four  hours  southwest  of  Arma  on  the 
Choquetira  trail,  looking 
northeast.  A  general  view 
of  the  Cordillera  looking 
east  at  this  point  (Fig.  186), 

1              ,,                                        p  ,-,  Fig.   184 — To  illustrate  the  cantine  of  the 

shows  the  appearance  of  the  g^owline.     a-b     is     the     snowline     depressed 

snowline   as   one  looks   along  toward  the  north  (right)  in  response  to  heavier 

.,       j3       ,          „    ,,                           -r  precipitation.     The   line   a-b   represents   a   de- 

the  flanks  of  the  range.    In     ^^^^^.^^  -^  ^^^  ^pp^^j^  ^.^^^^.^^  ^^^  ^^  ^^^ 

detail  the  snowline  is  fur-  different  degree  of  insolation  on  tlie  northern 
■  1  T       J     1    1         J  (sunny)    and  southern    (shady)    slopes. 

ther  complicated  by  topog- 
raphy and  varying  insolation,  each  spur  having  a  snow- clad  and 
snow-free  aspect  as  sho^\^l  in  the  last  figure.    The  degree  of  dif- 
ference on  these  minor  slopes  may  even  exceed  the  difference 
between  opposite  aspects  of  the  range  in  which  they  occur. 

To  these  diversifying  influences  must  be  added  the  effect  of 
warm  up-valley  winds  that  precede  the  regular  afternoon  snow 
squalls  and  that  rdelt  the  latest  fall  of  snow  to  exceptionally  high 
elevations  on  both  the  valley  floor  and  the  spurs  against  which 
they  impinge.  The  influence  of  the  warmer  air  current  is  notably 
confined  to  the  heads  of  those  master  valleys  that  run  do^vn  the 
wind,  as  in  the  valley  heading  at  the  first  pass,  Cordillera  Vilca- 
pampa, and  at  the  heads  of  the  many  valleys  terminating  at  the 
passes  of  the  Maritime  Cordillera.  Elsewhere  the  winds  are  dis- 
sipated in  complex  systems  of  minor  valleys  and  their  effect  is 
too  well  distributed  to  be  recognized. 

It  is  clear  from  the  conditions  of  the  problem  as  outlined  on 
preceding  pages  that  the  amount  of  canting  may  be  expressed  in 
feet  of  difference  of  the  snowline  on  opposite  sides  of  a  range  or 


280 


THE  ANDES  OF  SOUTHERN  PERU 


in  degrees.  The  former  method  has,  heretofore,  been  employed. 
It  is  proposed  that  this  method  should  be  abolished  and  degrees 
substituted,  on  the  following  grounds :  Let  A  and  B,  Fig.  190,  rep- 
resent two  mountain  masses  of  unequal  area  and  unequal  eleva- 
tion. Let  the  opposite  ends  of  the  snowlines  of  both  figures  lie 
1,000  feet  apart  as  between  the  windward  and  leeward  sides  of  a 

broad  cordillera  (A),  or  as 


between  the  relatively  sun- 
nier and  relatively  shadier 
slopes  of  individual  moun- 
tains or  narrow  ranges  in 
high  latitudes  or  high  alti- 
tudes (B).  With  increasing 
elevation  there  is  increasing 
contrast  between  tempera- 
tures in  sunshine  and  in 
shade,  hence  a  greater  de- 
gree of  canting  (B).  Tend- 
ing toward  a  still  greater 
degree  of  contrast  is  the  ef- 
fect of  the  differences  in  the 
amounts  of  snowy  precipita- 
tion, which  are  always  more 
marked  on  an  isolated  and 
lofty  mountain  summit  than 
upon  a  broad  mountain 
mass  (1)  because  in  the 
former  there  is  a  very  re- 
stricted   area    where    snow 


Fig.  1S5 — Glacial  features  in  the  Peru- 
vian Andes  near  Arequipa.  Sketched  from  a 
railway  train,  July,  1911.  The  horizontal 
broken  lines  represent  the  lower  limit  of  light 
snow  during  late  June,  1911.  There  is  a  fine 
succession  of  moraines  in  U-shaped  valleys  in 
all  the  mountains  of  tlu;  Arequipa  region.  A 
represents  a  part  of  Chacchani  northwest  of 
Arequipa;  li  is  looking  south  by  east  at  <lie 
northwest  end  of  Chachani  near  Pampa  dr 
Arrieros;  C  also  shows  the  northwest  end  nf 
riiaenhani    from   a   more  distant  point. 


may  accumulate,  and  (2) 
because  witli  increase  of  elevation  there  is  a  rapid  and  differential 
decrease  in  both  llic  rate  of  adiabatic  cooling  and  the  amount  of 
water  vapor;  licjice  the  snow  producing  forces  are  more  quickly 
dissipated. 

Furthermore,  IIk;  Icfwnrd  side  of  a  lof'ly  mountain  not  only 
receives  much  less  snow  j>ropoilioii;illy  ilmn  ilic  leeward  side  of 


Fig.   186. 


Flu.   1S7. 


Fig.  18G — Canted  snowline  in  the  Cordillera  Vilcapanipa  between  Arma  and 
Choquetira.     Looking  east  from   13,500  feet. 

Fig.  187 — Glacial  topography  between  Lambrama  and  Antabamba  in  the  Central 
Ranges.  A  recent  fall  of  snow  covers  tlie  foreground.  The  glaciers  are  now  almost 
extinct  and  their  action  is  confined  to  the  deepening  and  steepening  of  the  cirques  at 
the  valley  heads. 


Fig.   ISS. 


Ik;     1S!». 


I'iri.  mS— As\  liillHt  li<;il  |n;il<s  ill  llii'  ('c'lltr;il  l!:ili;,n  s  iictwrrii  A  li)  nlin  inli:i  ,U1<1 
I.iiiiilirjiirui.  The  ^-iKuv-lillcd  liollows  in  the  plKilii/^Mapli,  f;ifc  ;i\\;iy  t'nim  (he  sun — tliiit 
i-.  south — and  liavc  n-taincd  snow  since  (he  ;;laeiai  e|M)(li:  while  llic  iiniljiern  slopes 
are  snow-free.  'I'liere  is  no  true  ^dacial  ire  ami  the  cunt  iniied  ciKiiic  recession  is  diK! 
to  nivation 

Fk;  1H!>  (Macinl  lopoj.'rapliy  north  nf  tiic  divide  on  the  seventy  tiiird  meridian, 
Maritime  Cordillera.     Looking  downstream   at  an   (hvalion   of    lti,.")()()   feet    (r»,0;50  m.). 


GLACIAL  FEATURES  281 

a  lower  mountain,  but  also  loses  it  faster  on  account  of  the 
smaller  extent  of  surface  upon  which  it  is  disposed  and  the  pro- 
portionally larger  extent  of  counteractive,  snow-free  surface 
about  it.  Among  the  volcanoes  of  Ecuador  are  many  that  show 
differences  of  500  feet  in  snowline  elevation  on  windward  and  lee- 
ward (east)  slopes  and  some,  as  for  example  Chimborazo,  that 
exhibit  differences  of  1,000  feet.    The  latter  figure  also  expresses 

iooo'.^--r-:^\.  cobradient 


Fig.  190 — To  illustrate  the  difference  in  the  degree  of  canting  of  the  snowline  on 
large  and  on  small  mountain  masses. 

the  differences  in  the  broad  Cordillera  Vilcapampa  and  in  the 
Maritime  Cordillera,  though  the  rate  of  canting  as  expressed  in 
degrees  is  much  greater  in  the  case  of  the  western  mountains. 

The  advantages  of  the  proposed  method  of  indicating  the  de- 
gree of  canting  of  the  snowline  lie  in  the  possibility  thus  afforded 
of  ultimately  separating  and  expressing  quantitatively  the  vari- 
ous factors  that  affect  the  position  of  the  line.  In  the  Cordillera 
Vilcapampa,  for  example,  the  dominant  canting  force  is  the  dif- 
ference between  sun  and  shade  temperatures,  while  in  the  vol- 
canoes of  Ecuador,  where  symmetrical  volcanoes,  almost  on  the 
equator,  have  equal  insolation  on  all  aspects  and  the  temperature 
contrasts  are  reduced  to  a  minimum — the  differences  are  owing 
chiefly  to  varying  exposure  to  the  winds.  The  elusive  factors  in 
the  comparison  are  related  to  the  differences  in  area  and  in  ele- 
vation. 

The  value  of  arriving  finally  at  close  snowline  analyses  grows 
out  of  (1)  the  possibility  of  snowline  changes  in  short  cycles  and 
(2)  uncertainty  of  arriving  by  existing  methods  at  the  snowline 
of  the  glacial  period,  whose  importance  is  fundamental  in  refined 
physiographic  studies  in  glaciated  regions  with  a  complex  topog- 
raphy.   To  show  the  application  of  the  latter  point  we  shall  now 


282  THE  ANDES  OF  SOUTHERN  PERU 

attempt  to  determine  the  snowline  of  the  glacial  period  in  the  belt 
of  country  along  the  route  of  the  Expedition. 

In  the  group  of  peaks  shown  in  Fig.  188  between  Lambrama 
and  Antabamba,  the  elevation  of  the  snowline  varies  from  16,000 
to  17,000  feet  (4,880-5,180  m.),  depending  on  the  topography  and 
the  exposure.  The  determination  of  the  limit  of  perpetual  snow 
was  here,  as  elsewhere  along  the  seventy-third  meridian,  based 
upon  evidences  of  nivation.  It  will  be  observed  in  Fig.  191  that 
just  under  the  snow  banks  to  the  left  of  the  center  are  streams  of 
i"ock  waste  which  head  in  the  snow.  Their  size  is  roughly  propor- 
tional to  the  size  of  the  snow  banks,  and,  furthermore,  they  are  not 
found  on  snow-free  slopes.  From  these  facts  it  is  concluded  that 
they  represent  the  waste  products  of  snow  erosion  or  nivation, 
just  as  the  hollows  in  which  the  snow  lies  represent  tl^e  topo- 
graphic products  of  nivation.  On  account  of  the  seasonal  and  an- 
nual variation  in  precipitation  and  temperature — hence  in  the  ele- 
vation of  the  snowline — it  is  often  difficult  to  make  a  correct  snow- 
line observation  based  upon  depth  and  apparent  permanence. 
Different  observers  report  great  changes  in  the  snowline  in  short 
intervals,  changes  not  explained  by  instrumental  variations,  since 
they  are  referred  to  topographic  features.  It  appears  to  be  im- 
possible to  rely  upon  present  records  for  small  changes  possibly 
related  to  minor  climatic  cycles  because  of  a  lack  of  standardiza- 
tion of  observations. 

Nothing  in  the  world  seems  simpler  at  first  sight  than  an  ob- 
servation on  the  elevation  of  the  snowline.  Yet  it  can  be  demon- 
strated that  large  numbers  of  observers  have  merely  noted  the 
position  of  temporary  snow.  It  is  strongly  urged  that  evidences 
of  nivation  servo  henceforth  as  proof  of  permanent  snow  and  that 
photographic  records  be  kept  for  comparison.  In  this  way  meas- 
urements of  changes  in  the  level  of  the  snowline  may  bo  accurately 
made  and  the  snow  cover  used  as  a  climatic  gauge. 

Farther  west  in  the  Maritime  Cordillera,  llio  snowline  rises  to 
18,000  feet  on  the  northern  slopes  of  the  mountains  and  to  17,000 
foet  on  the  southern  slopes.  The  top  of  the  pass  above  Cotahuasi, 
17,600  feet  (5,360  m.),  was  snow-free  in  October,  1911,  but  the 


>':.'-iii 


mi^u^^ 


'^^^^^^^^^1 

III 

!>'  f.'i'-'.Vfo.'.  ^^..^^US^^^^^^I 

E 

l^^^^^^l 

^ 

fe;^:^^ 

..F-^Sk 

'^^^^^^^^^^1 

; 

'^™ 

.. 

GLACIAL  FEATURES  283 

snow  extended  500  feet  lower  on  the  southern  slope.  The  degree 
of  canting  is  extraordinary  at  this  point,  single  volcanoes  only 
1,500  to  2,000  feet  above  the  general  level  and  with  bases  but  a 
few  miles  in  circumference  exhibit  a  thousand  feet  of  difference 
in  the  snowline  upon  northern  and  southern  aspects.  This 
is  to  be  attributed  no  less  to  the  extreme  elevation  of  the  snow 
(and,  therefore,  stronger  contrasts  of  shade  and  sun  tempera- 
tures) than  to  tl^e  extreme  aridity  of  the  region  and  the  high  day- 
time temperatures.  The  aridity  is  a  factor,  since  heavy  snowfall 
means  a  lengthening  of  the  period  of  precipitation  in  which  a 
cloud  cover  shuts  out  the  sun  and  a  shortening  of  the  period  of 
insolation  and  melting. 

Contrasts  between  shade  and  sun  temperatures  increase  with 
altitude  but  their  effects  also  increase  in  time.  Of  two  volcanoes 
of  equal  size  and  both  20,000  feet  above  sea  level,  that  one  will 
show  the  greater  degree  of  canting  that  is  longer  exposed  to  the 
sun.  The  high  daytime  temperature  is  a  factor,  since  it  tends  to 
remove  the  thinnest  snow,  which  also  falls  in  this  case  on  the  side 
receiving  the  greatest  amount  of  heat  from  the  sun.  The  high 
daytime  temperature  is  phenomenal  in  this  region,  and  is  owing 
to  the  great  extent  of  snow-free  land  at  high  elevations  and  yet 
below  the  snowline,  and  to  the  general  absence  of  clouds  and  the 
thinness  of  vegetation. 

On  approach  to  the  Avestern  coast  the  snowline  descends  again 
to  17,500  feet  on  Coropuna.  There,  are  three  chief  reasons  for 
this  condition.  First,  the  well-watered  Majes  Valley  is  deeply 
incised  almost  to  the  foot  of  Coropuna,  above  Chuquibamba,  and 
gives  the  daily  strong  sea  breeze  easy  access  to  the  mountain. 
Second,  the  Coast  Eange  is  not  only  low  at  the  mouth  of  the  Majes 
Valley,  but  also  is  cut  squarely  across  by  the  valley  itself,  so  that 
heavy  fogs  and  cloud  sweep  inland  nightly  and  at  times  completely 
cover  both  valley  and  desert  for  an  hour  after  sunrise.  Although 
these  yield  no  moisture  to  the  desert  or  the  valley  floor  except 
such  as  is  mechanically  collected,  yet  they  do  increase  the  precipi- 
tation upon  the  higher  elevations  at  the  valley  head. 

A  third  factor  is  the  size  of  Coropuna  itself.    The  mountain 


284  THE  ANDES  OF  SOUTHERN  PERU 

is  not  a  simple  volcano  but  a  composite  cone  with  five  main  sum- 
mits reaching  well  above  the  snowline,  the  highest  to  an  elevation 
of  21,703  feet  (6,615  m.).    It  measures  about  20  miles  (32  km.)  in 
circumference  at  the  snowline  and  45  miles  (72  km.)  at  its  base 
(measuring  at  the  foot  of  the  steeper  portion),  and  stands  upon 
a  great  tributary  lava  plateau  from  15,000  to  17,000  feet  above 
sea  level.     Compared  with  El  Misti,  at  Arequipa,  its  volume  is 
three  times  as  great,  its  height  two  thousand  feet  more,  and  its 
access  to  ocean  winds  at  least  thirty  per  cent  more  favorable.    El 
Misti,  19,200  feet  (5,855  m.)  has  snow  dovm  as  far  as  16,000  feet 
in  the  wet  season  and  rarely  to  14,000  feet,  though  by  sunset  a 
fall  of  snow  may  almost  disappear  whose  lower  limit  at  sunrise 
was  16,000  feet.    Snow  may  accumulate  several  thousand  feet  be- 
low the  summit  during  the  wet  season,  and  in  such  quantities  as 
to  require  almost  the  whole  of  the  ensuing  dry  season  (March  to 
December)  for  its  melting.    Northward  of  El  Misti  is  the  massive 
and  extended  range,  Chachani,  20,000  feet  (6,100  m.)  high;  on  the 
opposite  side  is  the  shorter  range  called  Pichu-Pichu.    Snow  lies 
throughout  the  year  on  both  these  ranges,  but  in  exceptional  sea- 
sons it  nearly  disappears  from  Chachani  and  wholly  disappears 
from  Pichu-Pichu,  so  that  the  snowline  then  rises  to  20,000  feet. 
It  is  considered  that  the  mean  of  a  series  of  years  would  give  a 
value  between  17,000  and  18,000  feet  for  the  snowline  on  all  the 
great  mountains  of  the  Arequipa  region.^  This  would,  however,  in- 
clude what  is  known  to  be  temporary  snow;  the  limit  of  "per- 
petual" snow,  or  the  true  snowline,  appears  to  lie  about  19,000 
I  feet  on  Chachani  and  above  El  Misti,  say  39,500  foot.    It  is  also 
above  the  crest  of  Piclm-Pichu.    The  snowline,  therefore,  appears 
to  rise  a  thousand  feet  from  Coropuna  to  El  Misti,  owing  chiefly 
I  to  the  poorer  exposure  of  llie  latter  to  the  sources  of  sno^vy  pre- 
cipitation. 

/  It  may  also  be  noted  that  the  effect  of  the  easy  access  of  the 
ocean  winds  in  the  Coropuna  region  is  also  seen  in  the.  increasing 
amount  of  vegetation  which  appears  in  the  most  favorable  situa- 

•  S.   T.   Bailoy,  Pfnivinn   T\Tftpornlogy,    1888-1890.     Ann.   Astron.   Obscrv.  of  ITar- 
vanl  Coll.,  Vol.  30,  Vt.  1,  1809,  pp.  1-3. 


GLACIAL  FEATURES  285 

tions.  Thus,  along  the  Salamanca  trail  only  a  few  miles  from  the 
base  of  Coropuna  are  a  few  square  kilometers  of  quenigo  wood- 
land generally  found  in  the  cloud  belt  at  high  altitudes;  for  ex- 
ample, at  14,000  feet  above  Lambrama  and  at  9,000  feet  on  the 
slope  below  Incahuasi,  east  of  Pasaje,  The  greater  part  of  the 
growth  is  disposed  over  hill  slopes  and  on  low  ridges  and  valley 
walls.  It  is,  therefore,  clearly  unrelated  as  a  whole  to  the  greater 
amount  of  ground-water  with  which  a  part  is  associated,  as  along 
the  valley  floors  of  the  streams  that  head  in  the  belt  of  perpetual 
snow.  The  appearance  of  this  growth  is  striking  after  days  of 
travel  over  the  barren,  clinkery  lava  plateau  to  eastward  that  has 
a  less  favorable  exposure.  The  quenigo  forest,  so-called,  is  of 
the  greatest  economic  value  in  a  land  so  desolate  as  the  vast  arid 
and  semi-arid  mountain  of  western  Peru.  Every  passing  traveler 
lays  in  a  stock  of  fire-wood  as  he  rests  his  beasts  at  noonday;  and 
long  journeys  are  made  to  these  curious  woodlands  from  both 
Salamanca  and  Chuquibamba  to  gather  fuel  for  the  people  of  the 
towns. 

NR^ATION 

The  process  of  nivation,  or  snow  erosion,  does  not  always  pro- 
duce visible  effects.  It  may  be  so  feeble  as  to  make  no  impression 
upon  very  resistant  rock  where  the  snow-fall  is  light  and  the 
declivity  low.  Ablation  may  in  such  a  case  account  for  almost  the 
whole  of  the  snow  removed.  On  strong  and  topographically 
varied  slopes  where  the  snow  is  concentrated  in  headwater  alcoves, 
there  is  a  more  pronounced  downward  movement  of  the  snow 
masses  with  more  prominent  effects  both  of  erosion  beneath  the 
snow  and  of  accumulation  at  the  border  of  the  snow.  In  such 
cases  the  limit  of  perpetual  snow  may  be  almost  as  definitely 
known  as  the  limit  of  a  glacier.  Like  glaciers  these  more  power- 
ful snow  masses  change  their  limits  in  response  to  regional 
changes  in  precipitation,  temperature,  or  both.  It  would  at  first 
sight  appear  impossible  to  distinguish  between  these  changes 
through  the  results  of  nivation.  Yet  in  at  least  a  few  cases  it  may 
be  as  readily  determined  as  the  past  limits  of  glaciers  are  inferred 


286  THE  ANDES  OF  SOUTHERN  PERU 

from  the  terminal  moraines,  still  intact,  that  cross  the  valley 
floors  far  below  the  present  limits  of  the  ice. 

In  discussing  the  process  of  nivation  it  is  necessary  to  assume 
a  sliding  movement  on  the  part  of  the  snow,  though  it  is  a  condi- 
tion in  Matthes'  original  problem  in  which  the  nivation  idea  was 
introduced  that  the  snow  masses  remain  stationary.  It  is  be- 
lieved, however,  that  Matthes'  valuable  observations  and  conclu- 
sions really  involve  but  half  the  problem  of  nivation;  or  at  the 
most  but  one  of  two  phases  of  it.  He  has  adequately  s]lo^^m  the 
manner  in  which  that  phase  of  nivation  is  expressed  which  we  find 
at  the  horder  of  the  snoiv.  Of  the  action  beneath  the  snow  he 
says  merely :  ' '  Owing  to  the  frequent  oscillations  of  the  edge  and 
the  successive  exposure  of  the  different  parts  of  the  site  to  frost 
action,  the  area  thus  affected  will  have  no  well-defined  boundaries. 
The  more  accentuated  slopes  will  pass  insensibly  into  the  flatter 
ones,  and  the  general  tendency  will  be  to  give  the  drift  site  a  cross 
section  of  smoothly  curved  outline  and  ordinarily  concave."* 

From  observations  on  the  effects  of  nivation  in  valleys,  Matthes 
further  concludes  that  ''on  a  grade  of  about  12  per  cent  .  .  . 
neve  must  attain  a  thickness  of  at  least  125  feet  in  order  that  it 
may  have  motion,'"  though  as  a  result  of  the  different  line  of 
observations  Hobbs  concludes  '  that  a  somewhat  greater  thickness 
is  required. 

The  snow  cover  in  tropical  mountains  offers  a  number  of  solid 
advantages  in  this  connection.  Its  limits,  especially  on  the  Cordil- 
lera Vilcapampa,  on  the  eastern  border  of  the  Andes,  are  subject 
to  small  seasonal  oscillations  and  the  edge  of  the  ** perpetual" 
snow  is  easily  determined.  Furthermore,  it  is  known  from  the 
comparatively  "fixed  quality  of  tropical  climate,"  as  Humboldt 
put  it,  that  the  variations  of  the  snowline  in  a  period  of  years  do 
not  exceed  rather  narrow  limits.  In  mid-latitudos  on  the  con- 
trary there  is  an  extraordinary  shifting  of  the  margin  of  the  snow 


•  ?.  E.  Matthes,  Glncinl  Sc-nlptnrc  of  tlio  Bigliorn  MountainB,  Wyoming,  Twentieth 
Ann.   Kept.  U.  S.  Cool.  Surv.,   ISDO-IDOO,  Pt.  2,  p.   181. 

'  Idem,  p.   ino. 

•  W.  H.  Hobbs,  Clinrnctcristicfl  of   Kxisting  Glaciers.  1011,  p.  22. 


Fig.  191. 


Fig.    192. 


Fig  191 — The  "pocked"  surface  characteristically  developed  in  the  zone  of  light 
nivation.     Compare  with  Fig.   194,  showing  the  effects  of  heavy  nivation. 

Fig.  192 — Steep  cirqiie  walls  and  valleys  head  in  the  Central  Ranges  between 
Lambrama  and  Chuquibambilla.  The  snow  is  here  a  vigorous  agent  in  transporting 
talus  material  and  soil  from  all  the  upper  slopes  down  to  the  foot  of  the  cirque  wall. 


/    *i^ 


Fig.   193. 


I'H,.    i:t 


Fia.  19.'{ — I'antii  Monntiiin  nnd  it-<  f,'l;i(iir  system.  'I'lic  Inlns-covcrod  mass  in  the 
CPnt*T  (H)  is  a  UTiniiial  iiudaini-  topped  liy  (lie  dirt-stiiined  f^liieier  tlint  descends 
from  tlie  ere.st.  Tlie  seiJiiiale  ^laeiers  were  formerly  iinited  to  form  a  liupe  ice  tonf^ie 
tliat  truncated  tlie  lateral  spurs  and  flattened  tlie  valley  floor.  One  of  its  former 
stages  is  hIiowii  Iiv  (lie  terminal  moraiin'  in  (lie  ini<l(lle  distance,  hreiielied  by  a  stream, 
and   impoiiiidin({  a   lake  not  visible   from    this   iinint,  of  view. 

I'li;  l!il  — Hece.sHcd  Honllieni  ^lnjies  of  volcanoes  wliose  norlliei'ii  slopes  are  prac- 
tically witlioiit  (flacial  modifications.  Summit  of  tlic  lava  plateau,  Maritime  Cordillera, 
^veatcrn   Peru,  between   Antabamba   and   (otaliuasi. 


GLACIAL  FEATURES  287- 

cover,  and  a  correspondingly  wide  distribution  of  the  feeble  ef- 
fects of  nivation. 

Test  cases  are  presented  in  Figs.  191,  192,  and  193,  Cordillera 
Vilcapampa,  for  the  determination  of  the  fact  of  the  movement 
of  the  snow  long  before  it  has  reached  the  thickness  Matthes  or 
Hobbs  believes  necessary  for  a  movement  of  translation  to  begin. 
Fig.  191  shows  snow  masses  occupying  pockets  on  the  slope  of  a 
ridge  that  was  never  covered  with  ice.  Past  glacial  action  with 
its  complicating  effects  is,  therefore,  excluded  and  we  have  to  deal 
with  snow  action  pure  and  simple.  The  pre-glacial  surface  with 
smoothly  contoured  slopes  is  recessed  in  a  noteworthy  way  from 
the  ridge  crest  to  the  snowline  of  the  glacial  period  at  least  a  thou- 
sand feet  lower.  The  recesses  of  the  figure  are  peculiar  in  that 
not  even  the  largest  of  them  involve  the  entire  surface  from  top 
to  bottom ;  they  are  of  small  size  and  are  scattered  over  the  entire 
slope.  This  is  believed  to  be  due  to  the  fact  that  they  represent 
the  limits  of  variations  of  the  snowline  in  short  cycles.  Below 
them  as  far  as  the  snowline  of  the  glacial  period  are  larger  re- 
cesses, some  of  which  are  terminated  by  masses  of  waste  as  exten- 
sive as  the  neighboring  moraines,  but  disposed  in  irregular  scal- 
lops along  the  borders  of  the  ridges  or  mountain  slopes  in  which 
the  recesses  have  been  found. 

The  material  accumulated  at  the  lower  limit  of  the  snow  cover 
of  the  glacial  period  was  derived  from  two  sources:  (1)  from 
slopes  and  cliffs  overlooking  the  snow,  (2)  from  beneath  the  snow 
by  a  process  akin  to  ice  plucking  and  abrasion.  The  first  process 
is  well  known  and  resembles  the  shedding  of  waste  upon  a  valley 
glacier  or  a  neve  field  from  the  bordering  cliffs  and  slopes.  Ma- 
terial derived  in  this  manner  in  many  places  rolls  down  a  long 
incline  of  snow  and  comes  to  rest  at  the  foot  of  it  as  a  fringe  of 
talus.  The  snow  is  in  this  case  but  a  substitute  for  a  normal  mass 
of  talus.  The  second  process  produces  its  most  clearly  recogniza- 
ble effects  on  slopes  exceeding  a  declivity  of  20° ;  and  upon  30° 
and  40°  slopes  its  action  is  as  well-defined  as  true  glacial  action 
which  it  imitates.  It  appears  to  operate  in  its  simplest  form  as 
if  independent  of  the  mass  of  the  snow,  small  and  large  snow 


288  THE  ANDES  OF  SOUTHERN  PERU 

patches  showing  essentially  the  same  results.  This  is  the  reverse 
of  Matthes'  conclusion,  since  he  says  that  though  the  minimum 
thickness  ''must  vary  inversely  with  the  percentage  of  the  grade," 
''the  influence  of  the  grade  is  inconsiderable,"  and  that  the  law 
of  variation  must  depend  upon  additional  observation.'^ 

Let  us  examine  a  number  of  details  and  the  argument  based 
upon  them  and  see  if  it  is  not  possible  to  frame  a  satisfactory  law 
of  variation. 

In  Fig.  193  the  chief  conditions  of  the  problem  are  set  forth. 
Forward  from  the  right-hand  peak  are  snow  masses  descending 
to  the  head  of  a  talus  {A)  whose  outlines  are  clearly  defined  by 
freshly  fallen  snow.  At  (B)  is  a  glacier  whose  tributaries  descend 
the  middle  and  left  slopes  of  the  picture  after  making  a  descent 
from  slopes  several  thousand  feet  higher  and  not  visible  in  this 
view.  The  line  beneath  the  glacier  marks  the  top  of  the  moraine 
it  has  built  up.  Moraines  farther  down  valley  show  a  former 
greater  extent  of  the  glacier.  Clearly  the  talus  material  at  (A) 
was  accumulated  after  the  ice  had  retreated  to  its  present  posi- 
tion. It  will  be  readily  seen  from  an  inspection  of  the  photograph 
that  the  total  amount  of  material  at  {A)  is  an  appreciable  fraction 
of  that  in  the  moraine.  The  ratio  appears  to  be  about  1 :  8  or  1 :  10. 
I  have  estimated  that  the  total  area  of  snow-free  surface  about 
the  snowfields  of  the  one  is  to  that  of  the  other  as  2:3.  The 
gradients  are  roughly  equivalent,  but  the  volume  of  snow  in  the 
one  case  is  but  a  small  fraction  of  that  in  the  other.  It  will  be 
seen  that  the  snow  masses  have  recessed  the  mountain  slopes  at  A 
and  formed  deep  hollows  and  that  the  hollowing  action  appears  to 
be  most  effective  where  the  snow  is  thickest. 

Summarizing,  we  note  first,  that  the  roughly  equivalent  factors 
are  gradient  and  amount  of  snow-free  surface;  second,  that  the 
unequal  factors  are  (a)  accumulated  waste,  (b)  degree  of  recess- 
ing, and  (c)  the  degree  of  compacting  of  snow  into  ice  and  a  cor- 
responding difference  in  the  character  of  the  glacial  agent,  and 
(d)   the  extent  of  the  snow  cover.     The  direct  and  important 


»  Op.  cit.,  p.  286.    Reference  on  p.  190, 


GLACIAL  FEATURES  289 

relation  of  the  first  two  unequal  factors  to  the  third  scarcely  need 
be  pointed  out. 

We  have  then  an  inequality  in  amount  of  accumulated  material 
to  be  explained  by  either  an  inequality  in  the  extent  of  the  snow 
and  therefore  an  inequality  of  snow  action,  or  an  inequality  due 
to  the  presence  of  ice  in  one  valley  and  not  in  the  other,  or  by 
both.  It  is  at  once  clear  that  if  ice  is  absent  above  (A)  and  the 
mountain  slopes  are  recessed  that  snow  action  is  responsible  for 
it.  It  is  also  recognized  that  whatever  rate  of  denudation  be  as- 
signed to  the  snow-free  surfaces  this  rate  must  be  exceeded  by 
the  rate  of  snow  action,  else  the  inequalities  of  slope  would  be 
decreased  rather  than  increased.  The  accumulated  material  at 
(A)  is,  therefore,  partly  but  not  chiefly  due  to  denudation  of  snow- 
free  surfaces.  It  is  due  chiefly  to  erosion  beneath  the  snow.  Nor 
can  it  be  argued  that  the  hollow^s  now  occupied  by  snow  were 
formed  at  some  past  time  when  ice  not  snow  lay  in  them.  They 
are  not  ice-made  hollows  for  they  are  on  a  steep  spur  above  the 
limits  of  ice  action  even  in  the  glacial  period.  Any  past  action  is, 
therefore,  represented  here  in  kind  by  present  action,  though  there 
would  be  differences  in  degree  because  the  heavier  snows  of  the 
past  were  displaced  by  the  lighter  snows  of  today. 

While  it  appears  that  the  case  presents  clear  proof  of  degrada- 
tion by  snow  it  is  not  so  clear  how  these  results  were  accomplished. 
Eeal  abrasion  on  a  large  scale  as  in  bowlder-shod  glaciers  is 
ruled  out,  since  glacial  striae  are  wholly  absent  from  nivated  sur- 
faces according  to  both  Matthes'  observations  and  my  own.  Yet 
all  nivated  surfaces  have  very  distinctive  qualities,  delicately  or- 
ganized slopes  which  show  a  marked  change  from  any  original 
condition  related  to  water-carving.  In  the  absence  of  striae,  the 
general  absence  of  all  but  a  thin  coating  of  waste  even  in  rock  hol- 
lows, and  the  accumulation  of  waste  up  to  bowlders  in  size  at  the 
lower  edge  of  the  nivated  zone,  I  conclude  that  compacted  snow 
or  neve  of  sufficient  thickness  and  gradient  may  actually  pluck 
rock  outcrops  in  the  same  manner  though  not  at  the  rate  which 
ice  exhibits.  That  the  products  of  nivation  may  be  bowlders  as 
well  as  fine  mud  would  seem  clearly  to  follow  increase  in  effectivcr 


290  THE  ANDES  OF  SOUTHERN  PERU 

ness,  due  to  increase  in  amount  of  tlie  accumulated  snow;  that 
bowlders  are  actually  transported  by  snow  is  also  sllo^^^l  by  their 
loresence  on  the  lower  margins  of  nivated  tracts. 

Our  argument  may  be  made  clearer  by  reference  to  the  ob- 
served action  of  snow  in  a  particular  valley.  Snow  is  shed  from 
the  higher,  steeper  slopes  to  the  lower  slopes  and  eventually  ac- 
cumulates to  a  marked  degree  on  the  bottoms  of  the  depressions, 
whence  it  is  avalanched  do^\Ti  valley  over  a  series  of  irregular 
steps  on  the  valley  floor.  An  avalanche  talces  place  through  the 
breaking  of  a  section  of  snow  just  as  an  iceberg  breaks  off  the 
end  of  a  tide-water  glacier.  Evidently  there  must  be  pressure 
from  behind  which  crowds  the  snow  forward  and  precipitates  it 
to  a  lower  level. 

As  a  snow  mass  falls  it  not  only  becomes  more  consolidated, 
beginning  at  the  plane  of  impact,  but  also  gives  a  shock  to  the 
mass  upon  which  it  falls  that  either  starts  it  in  motion  or  acceler- 
ates its  rate  of  motion.  The  action  must  therefore  be  accom- 
panied by  a  drag  upon  the  floor  and  if  the  rock  be  close-jointed 
and  the  blocks,  defined  by  the  joint  planes,  small  enough,  they  will 
be  transported.  Since  snow  is  not  so  compact  as  ice  and  permits 
included  blocks  easily  to  adjust  themselves  to  new  resistances,  we 
should  expect  the  detached  blocks  included  in  the  snow  to  change 
their  position  constantly  and  to  form  irregular  scratches,  but  not 
parallel  strirc  of  the  sort  confidently  attributed  to  stone-shod  ice. 

It  is  to  the  plasticity  of  snow  that  we  may  look  for  an  ex- 
planation of  the  smooth-contoured  appearance  of  the  landscape  in 
the  foreground  of  Fig.  135.  The  smoothly  curved  lines  are  best 
developed  where  the  entire  surface  was  covered  with  snow,  as  in 
mid-elevations  in  the  larger  snowfields.  At  higher  elevations, 
where  the  relief  is  sharper,  tlie  snow  is  shed  from  the  steeper 
declivities  and  collected  in  the  minor  basins  and  valley  heads, 
where  its  action  tends  to  sniootli  a  floor  of  limited  area,  while 
snow-free  surfaces  retain  all  llicir  original  irregularities  of  form 
or  are  actually  sharpened. 

Tlie  degree  of  effectiveness  of  snow  and  neve  action  may  be 
estimated  I'loin  the  reversed  slopes  now  marked  by  ponds  or  small 


GLACIAL  FEATURES  291 

marshy  tracts  scattered  throughout  the  former  neve  fields,  and 
the  many  niched  hollows.  They  are  developed  above  Pampaconas 
in  an  admirable  manner,  though  their  most  perfect  and  general 
development  is  in  the  summit  belt  of  the  Cordillera  Vilcapampa 
between  Arma  and  Choquetira,  Fig.  135.  It  is  notable  in  all  cases 
where  nivation  was  associated  with  the  work  of  valley  glaciers 
that  the  rounded  nivated  slopes  break  rather  sharply  with  the 
steep  slopes  that  define  an  inner  valley,  whose  form  takes  on  the 
flat  floor  and  under-cut  marginal  walls  normal  to  valley  glaciation. 

A  classification  of  numerous  observations  in  the  Cordillera 
Vilcapampa  and  in  the  Maritime  Cordillera  between  Lambrama 
and  Antabamba  may  now  be  presented  as  the  basis  for  a  tenta- 
tive expression  of  the  law  of  variation  respecting  snow  motion. 
The  statement  of  the  law  should  be  prefaced  by  the  remark  that 
thorough  checking  is  required  under  a  wider  range  of  conditions 
before  we  accept  the  law  as  final.  Near  the  lower  border  of  the 
snow  where  rain  and  hail  and  alternate  freezing  and  thawing  take 
place,  the  snow  is  compacted  even  though  but  fifteen  to  twenty  feet 
thick,  and  appears  to  have  a  down-grade  movement  and  to  exer- 
cise a  slight  drag  upon  its  floor  w^hen  the  gradient  does  not  fall 
below  20°.  Distinct  evidences  of  nivation  were  observed  on  slopes 
with  a  declivity  of  5°  near  summit  areas  of  past  glacial  action, 
where  the  snow  did  not  have  an  opportunity  to  be  alternately 
frozen  and  thawed. 

The  thickness  of  the  former  snow  cover  could,  however,  not  be 
accurately  determined,  but  was  estimated  from  the  topographic 
surroundings  to  have  been  at  least  several  hundred  feet.  Upon 
a  40°  slope  a  snow  mass  50  feet  thick  was  observed  to  be  break- 
ing off  at  a  cliff-face  along  the  entire  cross-section  as  if  impelled 
forward  by  thrust,  and  to  be  carrying  a  small  amount  of  waste 
— enough  distinctly  to  discolor  the  lowermost  layers — which  was 
shed  upon  the  snowy  masses  below.  With  increase  in  the  degree 
of  compactness  of  the  snow  at  successively  lower  elevations  along 
a  line  of  snow  discharge,  gradients  do^vn  to  25°  were  still  observed 
to  carry  strongly  crevassed,  waste-laden  snow  down  to  the  melt- 
ing border.     It  appeared  from  the  clear  evidences  of  vigorous 


292  THE  ANDES  OF  SOUTHERN  PERU 

action — the  accumulation  of  waste,  the  strong  crevassing,  the 
stream-like  character  of  the  discharging  snow,  and  the  pro- 
nounced topographic  depression  in  which  it  lay — that  much  flatter 
gradients  would  ser^^e,  possibly  not  more  than  15°,  for  a  snow 
mass  150  feet  wide,  30  to  40  feet  thick,  and  serving  as  the  out- 
let for  a  set  of  tributary  slopes  about  a  square  mile  in  area 
and  vdth.  declivities  ranging  from  small  precipices  to  slopes  of  30°. 

We  may  say,  therefore,  that  the  factors  affecting  the  rate  of 
motion  are  (1)  thickness,  (2)  degree  of  compactness,  (3)  diurnal 
temperature  changes,  and  (4)  gradient.  Among  these,  diurnal 
temperature  changes  operate  indirectly  by  making  the  snow  more 
compact  and  also  by  inducing  motion  directly.  At  higher  eleva- 
tions above  the  snowline,  temperature  changes  play  a  decreas- 
ingiy  important  part.  The  thickness  required  varies  inversely  as 
the  gradient,  and  upon  a  20°  slope  is  20  feet  for  wet  and  compact 
snow  subjected  to  alternate  freezing  and  thawing.  For  dry  snow 
masses  above  the  zone  of  effective  diurnal  temperature  changes, 
an  increasing  gradient  is  required.  With  a  gradient  of  40°,  less 
than  50  feet  of  snow  will  move  en  masse  if  moderately  compacted 
under  its  own  weight;  if  further  compacted  by  impact  of  falling 
masses  from  above,  the  required  thickness  may  diminish  to  40 
feet  and  the  required  declivity  to  15°.  The  gradient  may  decrease 
to  0°  or  actually  be  reversed  and  motion  still  continue  provided 
the  compacting  snow  approach  true  neve  or  even  glacier  ice  as  a 
limit. 

From  tlie  sharp  topographic  break  between  the  truly  glaciated 
portions  of  the  valley  in  regions  subjected  to  temporary  glacia- 
i'lon,  it  is  concluded  that  the  eroding  power  of  the  moving  mass 
is  suddenly  increased  at  llie  point  where  neve  is  finally  trans- 
formed into  true  ice.  This  transformation  must  be  assumed  to 
take  place  suddenly  to  account  for  so  sudden  a  change  of  function 
as  the  topograpliic  break  re(]uiros.  Below  the  point  at  which  the 
transformation  occurs  the  motion  takes  place  under  a  new  set  of 
conditions  whose  laws  have  already  been  formulated  by  students 
of  glaciology. 

The  foregoing  readings  of  gradient  and  depth  of  snow  are 


GLACIAL  FEATURES 


293 


typical  of  a  large  number  which  were  made  in  the  Peruvian  Andes 
and  which  have  served  as  the  basis  of  Fig.  195.  It  will  be  observed 
that  between  15°  and  20°  there  is  a  marked  change  of  function  and 
again  between  +5°  and  — 5°  declivity,  giving  a  double  reversed 
curve.  The  meaning  of  the  change  between  15°  and  20°  is  inferred 
to  be  that,  with  gradients  over  20°,  snow  cannot  wholly  resist 


300 


250 


ZOO 


150 


100 


50 


CURVE   OF  SNOW  MOTION 


-  50  0"  5°  10"  15°  20°  25"  30°  35°  40° 

Fig.  195 — Curve  of  snow  motion.  Based  on  many  observations  of  snow  motion  to 
show  minimum  tliickness  of  snow  required  to  move  on  a  given  gradient.  Figures  on 
the  left  represent  thickness  of  snow  in  feet.  The  degrees  represent  the  gradient  of  the 
surface.  The  gradients  have  been  run  in  sequence  down  to  0°  for  the  sake  of  com- 
pleting the  accompanying  discussion.  Obviously  no  glacially  unmodified  valley  in  a 
region  of  mountainous  relief  would  start  with  so  low  a  gradient,  though  glacial  action 
would  soon  bring  it  into  existence.  Between  -f5°  and  — 5°  the  curve  is  based  on  the 
gradients   of   nivated   surfaces. 

gravity  in  the  presence  of  diurnal  temperature  changes  across  the 
freezing  point  and  occasional  snow  or  hail  storms.  With  increase 
of  thickness  compacting  appears  to  progress  so  rapidly  as  to 
permit  the  transfer  of  thrust  for  short  distances  before  absorp- 
tion of  thrust  takes  place  in  the  displaced  snow.  At  250  feet 
thorough  compacting  appears  to  take  place,  enabling  the  snow  to 
move  out  under  its  own  weight  on  even  the  faintest  slopes ;  while, 


294;  THE  ANDES  OF  SOUTHERN  PERU 

with  a  thickness  still  greater,  the  resulting  neve  may  actually  be 
forced  up  slight  inclines  whose  declivity  appears  to  approach  5° 
as  a  limit.  I  have  nowhere  been  able  to  find  in  truly  nivated  areas 
reversed  curves  exceeding  5°,  though  it  should  be  added  that  de- 
pressions whose  leeward  slopes  were  reversed  to  2°  and  3°  are 
fairly  common.  If  the  curve  were  continued  we  should  undoubt- 
edly find  it  again  turning  to  the  left  at  the  point  where  the  thick- 
ness of  the  snow  results  in  the  transformation  of  snow  to  ice. 
From  the  sharp  topographic  break  observed  to  occur  in  a  narrow 
belt  between  the  neve  and  the  ice,  it  is  inferred  that  the  erosive 
power  of  the  neve  is  to  that  of  the  ice  as  2:4  or  1:5  for  equal 
areas;  and  that  reversed  slopes  of  a  declivity  of  10°  to  15°  may 
be  formed  by  glaciers  is  well  kno^^^l,  Precisely  what  thickness  of 
snow  or  neve  is  necessary  and  what  physical  conditions  effect  its 
transformation  into  ice  are  problems  not  included  in  the  main 
theme  of  this  chapter. 

It  is  important  that  the  proposed  curve  of  snow  motion  under 
minimum  conditions  be  tested  under  a  large  variety  of  circum- 
stances. It  may  possibly  be  found  that  each  climatic  region  re- 
quires its  special  modifications.  In  tropical  mountains  the  sud- 
den alternations  of  freezing  and  thawing  may  effect  such  a  high 
degree  of  compactness  in  the  snow  that  lower  minimum  gradients 
are  required  than  in  the  case  of  mid-latitude  mountains  where 
the  perpetual  snow  of  the  high  and  cold  situations  is  compacted 
through  its  own  weight.  Observations  of  the  character  introduced 
here  are  still  unattainable,  however.  It  is  hoped  that  they  will 
rapidly  increase  as  their  significance  becomes  apparent;  and  that 
they  have  high  significance  the  striking  nature  of  the  curve  of 
motion  seems  clearly  to  establish. 

BERGSCHRUNDS    AND    CIRQUES 

The  facts  brought  out  by  the  curve  of  snow-motion  (Fig.  195) 
have  an  immediate  bearing  on  the  development  of  cirques,  whose 
precise  mode  of  origin  and  development  have  long  been  in  doubt. 
Without  reviewing  tlic  arguments  upon  wlilcli  ilic  \ari()iis  hy- 
potheses rest,  we  shall  begin  at  once  with  the  strongest  explana- 


GLACIAL  FEATURES  295 

tion — W.  D.  Johnson's  famous  bergschrund  hypothesis.  The 
critical  condition  of  this  hypothesis  is  the  diurnal  migration 
across  the  freezing  point  of  the  air  temperature  at  the  bottom  of 
the  schrund.  Alternate  freezing  and  thawing  of  the  water  in  the 
joints  of  the  rock  to  which  the  schrund  leads,  exercise  a  quarry- 
ing effect  upon  the  rock  and,  since  this  effect  is  assumed  to  take 
place  at  the  foot  of  the  cirque,  the  result  is  a  steady  retreat  of 
the  steep  cirque  wall  through  basal  sapping. 

While  Johnson's  hypothesis  has  gained  wide  acceptance  and 
is  by  many  regarded  as  the  final  solution  of  the  cirque  problem 
it  has  several  weaknesses  in  its  present  form.  In  fact,  I  believe 
it  is  but  one  of  two  factors  of  equal  importance.  In  the  first 
place,  as  A.  C.  Andrews  ^  has  pointed  out,  it  is  extremely  improb- 
able that  the  bergschrund  of  glacial  times  under  the  conditions  of 
a  greater  volume  of  snow  could  have  penetrated  to  bedrock  at  the 
base  of  the  cirque  where  the  present  change  of  slope  takes  place. 
In  the  second  place,  the  assumption  is  untenable  that  the  berg- 
schrund in  all  cases  reaches  to  or  anywhere  near  the  foot  of  the 
cirque  wall.  A  third  condition  outside  the  hypothesis  and  con- 
tradictory to  it  is  the  absence  of  a  bergschrund  in  snowfields  at 
many  valleys  heads  where  cirques  are  w^ell  developed! 

Johnson  himself  called  attention  to  the  slender  basis  of  ob- 
servation upon  which  his  conclusions  rest.  In  spite  of  his  own 
caution  with  respect  to  the  use  of  his  meager  data,  his  hypothesis 
has  been  applied  in  an  entirely  too  confident  manner  to  all  kinds 
of  cirques  under  all  kinds  of  conditions.  Though  Johnson  de- 
scended an  open  bergschrund  to  a  rock  floor  upon  which  ice  rested, 
his  observations  raise  a  number  of  proper  questions  as  to  the 
application  of  these  valuable  data:  How  long  are  bergschrunds 
open?  How  often  are  they  open?  Do  they  everj'w^here  open  to 
the  foot  of  the  cirque  wall?  Are  they  present  for  even  a  part  of 
the  year  in  all  well-developed  cirques?  Let  us  suppose  that  it 
is  possible  to  find  many  cirques  filled  with  snow,  not  ice,  sur- 
rounded by  truly  precipitous  walls  and  with  an  absence  of  berg- 

*  Corrosion    of   Gravity    Streams   with    Application   of  the   Ice   Flood   Hypothesis, 
Journ.  and  Proc.  of  the  Royal  Society  of  N.  S.  Wales,  Vol.  43,  1909,  p.  286. 


296  THE  ANDES  OF  SOUTHERN  PERU 

sclirunds,  how  shall  we  explain  the  topographic  depressions  ex- 
cavated underneath  the  snowf  If  cirque  formation  can  be  shown 
to  take  phice  without  concentrated  frost  action  at  the  foot  of  the 
bergschrund,  then  is  the  bergschrund  not  a  secondary  rather  than 
a  primary  factor?  And  must  we  not  further  conclude  that  when 
present  it  but  hastens  an  action  which  is  common  to  all  snow-cov- 
ered recesses? 

It  is  a  pleasure  to  say  that  we  may  soon  have  a  restatement  of 
the  cirque  problem  from  the  father  of  the  bergschrund  idea.  The 
argument  in  this  chapter  was  presented  orally 
to  him  after  he  had  remarked  that  he  was  glad 
to  know  that  some  one  was  finding  fault  mth  his 
hypothesis.  ''For,"  he  said,  with  admirable 
spirit,  "I  am  about  to  make  a  most  violent 
attack  upon  the  so-called  Johnson  h}T)othesis." 
I  wish  to  say  frankly  that  while  he  regards 
Fig.    19G— Roia-    ^^^  following  argument  as  a  valid  addition  to 

tion  of  cirque  wall  to  o         o 

trough's  end  at  the    the  problem,  he  does  not  tbink  that  it  solves 
head  of  a  glaciated    ^^^  problem.     There  are  many  of  us  who  will 

valley.       The     ratio  ^ 

of  the  inner  to  the    read    his    ncw    explanation    with    the    deepest 

outer  radius  is  1:4.      j^terest. 

AVe  shall  begin  with  the  familiar  fact  that  many  valleys,  now 
without  perpetual  snow,  formerly  contained  glaciers  from  500  to 
1,000  feet  thick  and  that  their  sno^vfields  were  of  wide  extent  and 
great  depth.  At  the  head  of  a  given  valley  where  the  snow  is 
crowded  into  a  small  cross-section  it  is  compacted  and  suffers  a  re- 
duction in  its  volume.  At  first  nine  times  the  volume  of  ice,  the 
gradually  compacting  neve  approaches  the  volume  of  ice  as  a  limit. 
At  the  foot  of  the  cir(iue  wall  we  may  fairly  assume  in  the  absence 
of  direct  observations,  a  volume  reduction  of  one-half  due  to  com- 
pacting. I>ni  tliis  is  offset  in  tlio  case  of  a  well-developed  cirque 
l)y  volume  increases  due  to  the  convergence  of  the  snow  from  the 
surrounding  slopes,  as  shown  in  Fig.  19G.  Taking  a  typical 
cirque  from  a  point  above  Vilcabamba  pueblo  I  find  that  the 
radius  of  tlie  trough's  end  is  to  the  radius  of  the  upper  wall 
of  the  cirque  as  1:4;  and  since  the  corresponding  surfaces  are 


GLACIAL  FEATURES 


297 


to  one  another  as  the  squares  of  their  similar  dimensions  we 
have  1:4  or  1 :  16  as  the  ratio  of  their  snow  areas.  If  no  com- 
pacting took  place,  then  to  acconmaodate  all  the  snow  in  the  glacial 
trough  would  require  an  increase  in  thickness  in  the  ratio  of 
1:4.  If  the  snow  were  compacted  to  half  its  original  volume  then 
the  ratio  would  be  1:2.     Now,  since  the  volume  ratio  of  ice  to 


Fig.  197 — Mode  of  cirque  formation.  Taking  the  facts  of  snow  depth  represented 
in  the  curve,  Fig.  195,  and  transposing  them  over  a  profile  (the  heavy  line)  which 
ranges  from  0°  declivity  to  50°,  we  find  that  the  greatest  excess  of  snow  occurs 
roughly  in  the  center.  Here  ice  will  first  form  at  the  bottom  of  the  snow  in  the 
advancing  hcmicycle  of  glaciation,  and  here  it  will  linger  longest  in  the  hemicycle 
of  retreat.  Here  also  there  will  be  the  greatest  mass  of  neve.  All  of  these  factors 
are  self-stimulating  and  will  increase  in  time  until  the  floor  of  the  cirque  is  flattened 
or  depressed  sufficiently  to  ofTset  through  uphill  ice-flow  the  augmented  forces  of 
erosion.  The  eiTects  of  self-stimulation  are  shown  by  "snow  increase";  the  ice  shoe 
at  the  bottom  of  the  cirque  is  expressed  by  "  ice  factor."  The  form  accompanying  both 
these  terms  is  merely  suggestive.  The  top  of  "  excess  snow "  has  a  gradient  char- 
acteristic of  the  surface  of  snow  fields.  A  preglacial  gradient  of  0°  is  not  permissible, 
but  I  have  introduced  it  to  complete  the  discussion  in  the  text  and  to  illustrate  the 
flat  floor  of  a  cirque.  A  bergschrund  is  not  required  for  any  stage  of  this  process, 
though  the  process  is  hastened  wherever  bergschrunds  exist. 

snow  is  1 : 9  and  the  thickness  of  the  ice  down  valley  is,  say  400 
feet,  the  equivalent  of  loose  snow  at  the  foot  of  the  cirque  must 
be  more  than  1 : 4  over  1:9  or  more  than  two  and  one-quarter 
times  thicker,  or  400  feet  thick;  and  would  give  a  pressure  of 
(900  -^  10)  X  62.5  pounds,  or  5,625  pounds,  or  a  little  less  than 
three  tons  per  square  foot.  Since  a  pressure  of  2,500  pounds  per 
square  foot  will  convert  snow  into  ice  at  freezing  temperature,  it 


298  THE  ANDES  OF  SOUTHERN  PERU 

is  clear  that  ice  and  not  snow  was  tlie  state  at  the  bottom  of  the 
mass  in  glacial  times.  Further,  between  the  surface  of  the  snow 
and  the  surface  of  the  bottom  layer  of  the  ice  there  must  have 
been  every  gradation  between  loose  snow  and  firm  ice,  with  the 
result  that  a  thickness  much  less  than  900  feet  must  be  assumed. 
Precisely  what  thickness  would  be  found  at  the  foot  of  the  cirque 
wall  is  unknown.  But  granting  a  thickness  of  400  feet  of  ice  an 
additional  300  feet  for  neve  and  snow  would  raise  the  total  to  700 
feet. 

The  application  of  the  facts  in  the  above  paragraph  is  clearly 
seen  when  we  refer  to  Fig.  197.  The  curve  of  snow  motion  of  Fig. 
195  is  applied  to  an  ungiaciated  mountain  valley.  Taking  a 
normal  snow  surface  and  filling  the  valley  head  it  is  seen  that 
the  excess  of  snow  depth  over  the  amount  required  to  give  motion 
is  a  measure  at  various  points  in  the  valley  head  and  at  different 
gradients  of  the  erosive  force  of  the  snow.  It  is  strikingly  con- 
centrated on  the  15° -20°  gradient  which  is  precisely  where  the  so- 
called  process  of  basal  sapping  is  most  marked.  If  long  continued 
the  process  will  lead  to  the  developing  of  a  typical  cirque  for  it  is 
a  process  that  is  self-stimulating.  The  more  the  valley  is  changed 
in  form  tlie  more  it  tends  to  change  still  further  in  form  because 
of  deepening  snowfields  until  cliffed  pinnacles  and  matterhorns 
result. 

By  further  reference  to  the  figure  it  is  clear  that  a  schrund 
350  feet  deep  could  not  exist  on  a  cirque  wall  with  a  declivity  of 
even  20°  without  being  closed  by  flow,  unless  we  grant  more  rapid 
flow  below  the  crevasse.  In  the  case  of  a  glacier  flowing  over  a 
nearly  flat  bed  away  from  the  circjue  it  is  difficult  to  conceive  of  a 
rate  of  flow  greater  than  that  of  snow  jmd  neve  on  the  steep  lower 
portion  of  the  cirque  wall,  when  movement  on  that  gradient  begins 
with  snow  but  20  feet  thick. 

In  contrast  to  this  is  the  view  that  the  schrund  line  should  lie 
well  up  the  cirque  wall  wliorc  the  snow  is  comparatively  thin  and 
where  tliere  is  an  approach  to  the  lower  limits  of  movement. 
The  sclirund  would  appear  to  open  where  the  bottom  material 
changes  its  form,  i.e.,  where  it  first  has  its  motion  accelerated  by 


GLACIAL  FEATURES  299 

transformation  into  neve.  In  this  view  the  schrund  opens  not  at 
the  foot  of  the  cirque  wall  but  well  above  it  as  in  Fig.  198,  in 
which  C  represents  snow  from  top  to  bottom;  B,  neve;  and  A,  ice. 
The  required  conditions  are  then  (1)  that  the  steepening  of  the 
cirque  wall  from  x  to  y  should  be  effected  by  sapping  originated 
at  y  through  the  agencies  outlined  by  Johnson;  (2)  that  the  steep- 
ening from  X  to  y  should  be  effected  by  sapping  originated  at  x 
through  the  change  of  the  agent  from  neve  to  ice  with  a  sudden 
change  of  function;  (3)  and  that  the  essential  unity  of  the  wall 
x-y-z  be  maintained  through  the  erosive  power  of  the  neve,  which 
would  tend  to  offset  the  formation  of  a  shelf  along  a  horizontal 
plane  passed  through  y.  The  last-named  process  not  only  appears 
entirely  reasonable  from  the  conditions  of  gradient  and  depth  out- 
lined on  pp.  296  to  298,  but  also  meets  the  actual  field  conditions  in 
all  the  cases  examined  in  the  Peruvian  Andes.  This  brings  up 
the  second  and  third  of  our  main  considerations,  that  the  berg- 
schrund  does  not  always  or  even  in  many  cases  reach  the  foot  of 
the  cirque  wall,  and  that  cirques  exist  in  many  cases  where  berg- 
schrunds  are  totally  absent. 

It  is  a  striking  fact  that  frost  action  at  the  bottom  of  the 
bergschrund  has  been  assumed  to  be  the  only  effective  sapping 
force,  in  spite  of  the  common  observation  that  bergschrunds  lie 
in  general  well  toward  the  upper  limits  of  snowfields — so  far,  in 
fact,  that  their  bottoms  in  general  occur  several  hundred  feet 
above  the  cirque  floors.  Is  the  cirque  under  these  circumstances 
a  result  of  the  schrund  or  is  the  schrund  a  result  of  the  cirque? 
In  ivliat  class  of  cirques  do  schrunds  develop?  If  cirque  develop- 
ment in  its  early  stages  is  not  marked  by  the  development  of 
bergschrunds,  then  are  bergschrunds  an  essential  feature  of 
cirques  in  their  later  stages,  however  much  the  sapping  process 
may  be  hastened  by  schrund  formation? 

Our  questions  are  answered  at  once  by  the  indisputable  facts 
that  many  schrunds  occur  well  toward  the  upper  limit  of  snow, 
and  that  many  cirques  exist  whose  sno^vfields  are  not  at  all  broken 
by  schrunds.  It  was  "with  great  surprise  that  I  first  noted  the 
bergschrunds   of  the   Central  Andes,   especially  after  becoming 


300  THE  ANDES  OF  SOUTHERN  PERU 

familiar  with  Johnson's  apparently  complete  proof  of  their 
genetic  relation  to  the  cirques.  But  it  was  less  surprising  to  dis- 
cover the  position  of  the  few  observed— high  up  on  the  cirque 
walls  and  always  near  the  upper  limit  of  the  snoAvfields. 

A  third  fact  from  regions  once  glaciated  but  now  snow-free 
also  combined  with  the  two  preceding  facts  in  weakening  the  whole- 
sale application  of  Johnson's  hypothesis.  In  many  headwater 
basins  the  cirque  whose  wall  at  a  distance  seemed  a  unit  was  really 
broken  into  two  unequal  portions;  a  lower,  much  grooved  and 
rounded  portion  and  an  upper  unglaciated,  steep-walled  portion. 
This  condition  was  most  puzzling  in  view  of  the  accepted  explana- 
tion of  cirque  formation,  and  it  was  not  until  the  two  first-named 
facts  and  the  applications  of  the  curves  of  snow  motion  were 
noted  that  the  meaning  of  the  break  on  the  cirque  became  clear. 

Referring  to  Fig.  198  we  see  at 
once  that  the  break  occurs  at  y 
and  means  that  under  favorable 
topographic  and  geologic  condi- 
tions sapping  at  y  takes  place 
faster  than  at  x  and  that  the  re- 

FiG.  198-The  dcvoiop.nont  of  ciniu.s.     treat  of  y-z  is  fastcr  than  x-y. 
See  text,  p.  299,  and  Fig.  199.  It  will  be  clcar  that  whcu  thcsc 

conditions  are  reversed  or  sapping  at  x  and  at  y  are  equal  a 
single  wall  will  result.  On  reference  to  the  literature  I  find  that 
Gilbert  recently  noted  this  feature  and  called  it  the  schrundline^ 
He  believes  that  it  marks  the  base  of  the  bergschrund  at  a  late 
stage  in  the  excavation  of  the  cirque  basin.  TTo  notes  further  that 
the  lower  less-steep  slope  is  glacially  scoured  and  that  it  forms 
"a  sort  of  shoulder  or  terrace." 

If  all  the  structural  and  topographic  conditions  were  known  in 
a  great  varicfy  of  gallicring  basins  wo  should  uiidoubtodly  find 
in  them,  and  not  in  special  forms  of  ice  erosion,  an  explanation 
of  the  various  forms  assumed  by  cirques.  The  limitations  in- 
herent in  a  high-altitude  field  and  a  limited  snow  cover  prevented 


•  O.    K.    Gilbfrt.    Syst^-mniic    Asymmetry   of   Crest   T.inrs    in    tlio   ITipli    Sierra    of 
Cnlifornia.     Jour.  Gcol.,  Vol.  12,  1904,  p.  582. 


GLACIAL  FEATURES  301 

me  from  solving  the  problem,  but  it  offered  sufficient  evidence  at 
least  to  indicate  the  probable  lines  of  approach  to  a  solution.  For 
example  it  is  noteworthy  that  in  all  the  cases  examined  the 
schrundline  was  better  developed  the  further  glacial  erosion  had 
advanced.  So  constantly  did  this  generalization  check  up,  that  if 
at  a  distance  a  short  valley  w^as  observed  to  end  in  a  cirque,  I 
knew  at  once  and  long  before  I  came  to  the  valley  head  that  a 
shoulder  below  the  schrundline  did  not  exist.  At  the  time  this 
observation  was  made  its  significance  w^as  a  mystery,  but  it  repre- 
sents a  condition  so  constant  that  it  forms  one  of  the  striking 
features  of  the  glacial  forms  in  the  headwater  region. 

The  meaning  of  this  feature  is  represented  in  Fig.  199,  in 
which  three  successive  stages  in  cirque  development  are  shown. 
In  A,  as  displayed  in  small  val- 
leys or  mountainside  alcoves 
which  were  but  temporarily  oc- 
cupied by  snow"  and  ice,  or  as  in 
all  higher  valleys  during  the 
earlier  stages  of  the  advancing  pig   199— Further  stages  in  the  de- 

hemicycle     of     glaciation,     snow       velopmcnt  of  cirques.     See  p.  299  and  Fig. 

collects,  a  short  glacier  forms, 

and  a  bergschrund  develops.  As  a  result  of  the  concentrated  frost 
action  at  the  base  of  the  bergschrund  a  rapid  deepening  and  steep- 
ening takes  place  at  a.  As  long  as  the  depth  of  snow  (or  snow  and 
neve)  is  slight  the  bergschrund  may  remain  open.  But  its  existence 
at  this  particular  point  is  endangered  as  the  cirque  grows,  since  the 
increasing  steepness  of  the  slope  results  in  more  rapid  snow  move- 
ment. Greater  depth  of  snow  goes  hand  in  hand  with  increasing 
steepness  and  thus  favors  the  formation  of  neve  and  even  ice  at 
the  bottom  of  the  moving  mass  and  a  constantly  accelerated  rate 
of  motion.  At  the  same  time  the  bergschrund  should  appear 
higher  up  for  an  independent  reason,  namely,  that  it  tends  to 
form  between  a  mass  of  slight  movement  and  one  of  greater 
movement,  which  change  of  function,  as  already  pointed  out, 
would  appear  to  be  controlled  by  change  from  snow  to  neve  or 
ice  on  the  part  of  the  bottom  material. 


302  THE  ANDES  OF  SOUTHERN  PERU 

The  first  stages  in  the  upward  migration  of  the  bergschrund 
will  not  effect  a  marked  change  from  the  original  profile,  since 
the  converging  slopes,  the  great  thickness  of  neve  and  ice  at  this 
point,  and  the  steep  gradient  all  favor  powerful  erosion.  "When, 
however,  stage  C  is  reached,  and  the  bergschrund  has  retreated 
to  c",  a  broader  terrace  results  below  the  schrundline,  the  gradient 
is  decreased,  the  ice  and  neve  (since  they  represent  a  constant  dis- 
charge) are  spread  over  a  greater  area,  hence  are  thinner,  and  we 
have  the  cirque  taking  on  a  compound  character  with  a  lower,  less 
steep  and  an  upper,  precipitous  section. 

It  is  clear  that  a  closely  jointed  and  fragile  rock  might  be 
quarried  by  moving  ice  at  c'-c"  and  the  cirque  wall  extended  un- 
broken to  X;  it  is  equally  clear  that  a  homogeneous,  unjointed  gran- 
ite would  offer  no  opportunities  for  glacial  plucking  and  would 
powerfully  resist  the  much  slower  process  of  abrasion.  Thus 
Gilbert  ^°  observed  the  schrundline  in  the  granites  of  the  Sierra 
Nevada,  which  are  "in  large  part  structureless"  and  my  own  ob- 
servations show  the  schrundline  well  developed  in  the  open- 
jointed  granites  of  the  Cordillera  Vilcapampa  and  wholly  absent 
in  the  volcanoes  of  the  Maritime  Cordillera,  where  ashes  and  cin- 
ders, the  late  products  of  volcanic  action,  form  the  easily  eroded 
walls  of  the  steep  cones.  Somewhere  between  these  extremes — 
lack  of  a  variety  of  observations  prevents  our  saying  where — the 
resistance  and  the  internal  structure  of  the  rock  will  just  permit 
a  cirque  wall  to  extend  from  x  to  c' "  of  Fig.  199. 

A  common  feature  of  cirques  that  finds  an  explanation  in  the 
proposed  hypothesis  is  the  notch  that  commonly  occurs  at  some 
point  where  a  convergence  of  slopes  above  the  main  cirque  wall 
concentrates  snow  discharge.  It  is  proposed  to  call  this  type  the 
notched  cirque.  It  is  highly  significant  that  these  notches  are 
commonly  marked  by  even  steeper  descents  at  the  point  of  dis- 
charge into  the  main  cirque  than  the  remaining  portion  of  the 
cirque  wall,  even  when  the  discharge  was  from  a  very  small 
basin  and  in  the  form  of  snow  or  at  the  most  neve.  The  excess  of 
discharge  at  a  point  on  the  l)asin  rim  ought  to  produce  the  form 

'"  ()[).  cit.,  |).  .'500;  reference  on  p.  582. 


GLACIAL  FEATURES  303 

we  find  there  under  the  conditions  of  snow  motion  outlined  in 
earlier  paragraphs.  It  is  also  noteworthy  that  it  is  at  such  a 
point  of  concentrated  discharge  that  crevasses  no  sooner  open  than 
they  are  closed  by  the  advancing  snow  masses.  To  my  mind  the 
whole  action  is  eminently  representative  of  the  action  taking 
place  elsewhere  along  the  cirque  wall  on  a  smaller  scale. 

What  seems  a  good  test  of  the  explanation  of  cirques  here 
proposed  was  made  in  those  localities  in  the  Maritime  Cordillera, 
where  large  snowbanks  but  not  glaciers  affect  the  form  of  the 
catchment  basins.  A  typical  case  is  sho^\^l  in  Fig.  201.  As  in 
many  other  cases  we  have  here  a  great  lava  plateau  broken  fre- 
quently by  volcanic  cones  of  variable  composition.  Some  are  of 
lava,  others  consist  of  ashes,  still  others  of  tuff  and  lava  and 
ashes.  At  lower  elevations  on  the  east,  as  at  16,000  feet  between 
Antabamba  and  Iluancarama,  evidences  of  long  and  powerful 
glaciers  are  both  numerous  and  convincing.  But  as  we  rise  still 
higher  the  glaciated  topography  is  buried  progressively  deeper 
under  the  varying  products  of  volcanic  action,  until  finally  at  the 
summit  of  the  lava  fields  all  evidences  of  glaciation  disappear  in 
the  greater  part  of  the  country  between  Huancarama  and  the 
main  divide.  Nevertheless,  the  summit  forms  are  in  many  cases 
as  significantly  altered  as  if  they  had  been  molded  by  ice.  Pre- 
cipitous cirque  walls  surround  a  snow-filled  amphitheater,  and 
the  process  of  deepening  goes  forward  under  one's  eyes.  No 
moraines  block  the  basin  outlets,  no  U-shaped  valleys  lead  for- 
ward from  them.  We  have  here  to  do  with  post-glacial  action 
pure  and  simple,  the  volcanoes  having  been  formed  since  the  close 
of  the  Pleistocene. 

Likewise  in  the  pass  on  the  main  divide,  the  perpetual  snow 
has  begun  the  recessing  of  the  very  recent  volcanoes  bordering 
the  pass.  The  products  of  snow  action,  muds  and  sands  up  to  very 
coarse  gravel,  glaciated  in  texture  with  an  intermingling  of 
blocks  up  to  six  inches  in  diameter  in  the  steeper  places,  are  col- 
lected into  considerable  masses  at  the  snowline,  where  they  form 
broad  sheets  of  waste  so  boggy  as  to  be  impassable  except  by  care- 
fully selected  routes.     No  ice  action  whatever  is  visible  below 


30i  THE  ANDES  OF  SOUTHERN  PERU 

the  snowline  and  the  snow  itself,  though  wet  and  compact,  is  not 
underlain  by  ice.  Yet  the  process  of  hollowing  goes  forward 
visibly  and  in  time  will  produce  serrate  forms.  In  neither  case 
is  there  the  faintest  sign  of  a  bergschrund;  the  gradients  seem 
so  well  adjusted  to  the  thickness  and  rate  of  movement  of  the 
snow  from  point  to  point  that  the  marginal  crack  found  in  many 
sno"\\iSelds  is  absent. 

The  absence  of  bergschrunds  is  also  noteworthy  in  many  locali- 
ties where  formerly  glaciation  took  place.  This  is  notoriously  the 
case  in  the  summit  zone  of  the  Cordillera  Vilcapampa,  where  the 
accumulating  snows  of  the  steep  cirque  walls  tumble  down  hun- 
dreds of  feet  to  gather  into  prodigious  snowbanks  or  to  form 
neve  fields  or  glaciers.  From  the  converging  walls  the  snowfalls 
keep  up  an  intermittent  bombardment  of  the  lower  central  snow 
masses.  It  is  safe  to  say  that  if  by  magic  a  bergschrund  could 
be  opened  on  the  instant,  it  would  be  closed  almost  immediately 
by  the  impetus  supplied  by  the  falling  snow  masses.  The  explana- 
tion appears  to  be  that  the  thicker  snow  and  neve  concentrated  at 
the  bottom  of  the  cirque  results  in  a  corresponding  concentration 
of  action  and  effect;  and  cirque  development  goes  on  without 
reference  to  a  bergschrund.  The  chief  attraction  of  the  berg- 
schrund hypothesis  lies  in  the  concentration  of  action  at  the  foot 
of  the  cirque  wall.  But  in  the  thickening  of  the  snow  far  beyond 
the  minimum  thickness  required  for  motion  at  the  base  of  the 
cirque  wall  and  its  change  of  function  with  transformation  into 
neve,  we  need  invoke  no  other  agent.  If  a  bergschrund  forms,  its 
action  may  take  place  at  the  foot  of  the  cirque  Avail  or  high  up  on 
the  wall,  and  yet  sapping  at  the  foot  of  the  wall  continue. 

From  which  we  conclude  (1)  that  where  frost  action  occurs  at 
the  bottom  of  a  bergschrund  opening  to  the  foot  of  the  cirque  wall 
it  aids  in  the  retreat  of  tlic  wall;  (2)  tliat  a  sapping  action  takes 
place  at  this  point  whether  or  not  a  bergschrund  exists  and  that 
bergschrund  action  is  not  a  necessary  part  of  cirque  formation; 
(3)  that  when  a  more  or  less  persistent  bergschrund  opens  on  the 
cirque  wall  above  its  foot  it  tends  to  develop  a  schrundline  with 
a  marked  terrace  below  it;  (4)  that  schrundlines  are  best  devel- 


sMles 


t/A/j 


V, 


^wi^. 


^^iiv 


<^/^:fCi^ 


1 


GLACIAL  FEATURES  305 

oped  in  the  mature  stages  of  topographic  development  in  the  gla- 
cial cycle;  (5)  that  the  varying  rates  of  snow,  neve,  and  ice  motion 
at  a  valley  head  are  the  persistent  features  to  which  we  must  look 
for  topographic  variations;  (6)  that  the  hypothesis  here  pro- 
posed is  applicable  to  all  cases  whether  they  involve  the  presence 
of  snow  or  neve  or  ice  or  any  combination  of  these,  and  whether 
bergschrunds  are  present  or  not;  and  (7)  at  the  same  time  affords 
a  reasonable  explanation  for  such  variations  in  forms  as  the  com- 
pound cirque  with  its  schrundline  and  terrace,  the  unbroken  cirque 
wall,  the  notched  cirque,  and  the  recessed,  snow-covered  mountain 
slopes  unaffected  by  ice. 

ASYMMETRICAL   CREST   LINES   AND  ABNORMAL   VALLEY   PROFILES   IN    THE 

CENTRAL   ANDES 

To  prove  that  under  similar  conditions  glacial  erosion  may  be 
greater  than  subaerial  denudation  quantitative  terms  must  be 
sought.  Only  these  will  carry  conviction  to  the  minds  of  many 
opponents  of  the  theory  that  ice  is  a  vigorous  agent  of  erosion. 
Gilbert  first  showed  in  the  Sierra  Nevada  that  headwater  glaciers 
eroded  more  rapidly  than  nonglacial  agents  under  comparable 
topographic  and  structural  conditions."  Oddly  enough  none  of 
the  supporters  of  opposing  theories  have  replied  to  his  argu- 
ments; instead  they  have  sought  evidence  from  other  regions  to 
show  that  ice  cannot  erode  rock  to  an  important  degree.  In  this 
chapter  evidence  from  the  Central  Andes,  obtained  in  1907  and 
1911,  will  be  given  to  show  the  correctness  of  Gilbert's  proposition. 

The  data  will  be  more  easily  understood  if  Gilbert's  argument 
is  first  outlined.  On  the  lower  slopes  of  the  glaciated  Sierra 
Nevada  asymmetry  of  form  resulted  from  the  presence  of  ice  on 
one  side  of  each  ridge  and  its  absence  on  the  other  (Fig.  200). 
The  glaciers  of  these  lower  ridges  were  the  feeblest  in  the  entire 
region  and  were  formed  on  slopes  of  small  extent ;  they  were  also 
short-lived,  since  they  could  have  existed  only  when  glacial  con- 
ditions had  reached  a  maximum.    Let  the  broken  line  in  the  upper 

"  Op.  cit.,  p.  300;  see  pp.  579-588  and  Fig.  8. 


306  THE  ANDES  OF  SOUTHERN  PERU 

part  of  the  figure  represent  the  preglacial  surface  and  the  solid 
line  beneath  it  the  present  surface.  It  will  not  matter  what  value 
we  give  the  space  between  the  two  lines  on  the  left  to  express  non- 
glacial  erosion,  since  had  there  been  no  glaciers  it  would  be  the 
same  on  both  sides  of  the  ridge.  The  feeble  glacier  occupying  the 
right-hand  slope  was  able  in  a  very  brief  period  to  erode  a  de- 
pression far  deeper  than  the  normal  agents  of  denudation  were 
able  to  erode  in  a  much  longer  period,  i.e.,  during  all  of  intergla- 
cial  and  postglacial  time.  Gilbert  concludes:  "The  visible  ice- 
made  hollows,  therefore,  represent  the  local  excess  of  glacial  over 
nonglacial  conditions." 

In  the  Central  Andes  are  many  volcanic  peaks  and  ridges 
formed  since  the  last  glacial  epoch  and  upon  them  a  remarkable 


SorSW  NorNE    S 

Fig.  200 — Diagrammatic  cross-section  Fig.  201 — Postglacial  volcano  recessed 

of  a  ridge  glaciated  on  one  side  only;  on  shady  southern  side  by  the  process  ot 
with  hypothetical  profile  (broken  line)  nivation.  Absolute  elevation  18,000  feet 
of   preglacial   surface.  (5,490    m.),    latitude    14°     S.,    Maritime 

Cordillera,  Peru. 

asjTumetry  has  been  developed.  Looking  southward  one  may  see 
a  smoothly  curved,  snow-free,  northward-facing  slope  rising  to  a 
crest  line  which  appears  as  regular  as  the  slope  leading  to  it. 
Looking  northward  one  may  sec  by  contrast  (Fig.  19-t)  sharp 
ridges,  whoso  lower  crests  are  serrate,  separated  by  deeply  re- 
cessed, snow-filled  mountain  hollows.  Below  this  highly  dissected 
zone  the  slopes  are  smooth.  The  smooth  slope  represents  the 
work  of  water ;  the  irregular  slopes  are  the  work  of  snow  and  ice. 
The  relation  of  the  north  and  south  slopes  is  diagrammatically 
shown  in  Fig.  201. 

To  demonstrate  the  erosive  effects  of  snow  and  ice  it  must  be 
shown:  (1)  that  the  iiiili.il  slopes  of  the  volcanoes  are  of  post- 
glacial age;  (2)  that  the  asymmetry  is  not  structural;  (3)  that  the 
snow-free  slopes  have  not  had  special  protection,  as  through  a 
more  abundant  plant  cover,  more  favorable  soil  texture,  or  other- 
wise. 


GLACIAL  FEATURES  307 

Proof  of  the  postglacial  origin  of  the  volcanoes  studied  in  this 
connection  is  afforded:  (1)  by  the  relation  of  the  flows  and  the 
ash  and  cinder  beds  about  the  bases  of  the  cones  to  the  glacial 
topography;  (2)  by  the  complete  absence  of  glacial  phenomena  be- 
low the  present  snowline.  Ascending  a  marginal  valley  (Fig.  202), 
one  comes  to  its  head,  where  two  tributaries,  with  hanging  rela- 
tions to  the  main  valley,  come  down  from  a  maze  of  lesser  valleys 
and  irregular  slopes.  Glacial  features  of  a  familiar  sort  are  every- 
where in  evidence  until  we  come  to  the  valley  heads.  Cirques,  re- 
versed grades,  lakes,  and  striae  are  on  every  hand.  But  at  alti- 
tudes above  17,200  feet,  recent  volcanic  deposits  have  over  large 
areas  entirely  obscured  the  older  glacial  topography.  The  glacier 
which  occupied  the  valley  of  Fig.  202  was  more  than  one-quarter 
of  a  mile  wide,  the  visible  portion  of  its  valley  is  now  over  six 
miles  long,  but  the  extreme  head  of  its  left-hand  tributary  is  so 
concealed  by  volcanic  material  that  the  original  length  of  the  gla- 
cier cannot  be  determined.  It  was  at  least  ten  miles  long.  From 
this  point  southward  to  the  border  of  the  Maritime  Cordillera  no 
evidence  of  past  glaciation  was  observed,  save  at  Solimana  and 
Coropuna,  where  slight  changes  in  the  positions  of  the  glaciers 
have  resulted  in  the  development  of  terminal  moraines  a  little  be- 
low the  present  limits  of  the  ice. 

From  the  wide  distribution  of  glacial  features  along  the  north- 
eastern border  of  the  Maritime  Cordillera  and  the  general  absence 
of  such  features  in  the  higher  country  farther  south,  it  is  con- 
cluded that  the  last  stages  of  volcanic  activity  were  completed  in 
postglacial  time.  It  is  equally  certain,  however,  that  the  earlier 
and  greater  part  of  the  volcanic  material  was  ejected  before 
glaciation  set  in,  as  shown  by  the  great  depth  of  the  canyons  (over 
5,000  feet)  cut  into  the  lava  flows,  as  contrasted  with  the  rela- 
tively slight  filling  of  coarse  material  which  was  accumulated  on 
their  floors  in  the  glacial  period  and  is  now  in  process  of  dissec- 
tion. Physiographic  studies  throughout  the  Central  Andes  demon- 
strate both  the  general  distribution  of  this  fill  and  its  glacial 
origin. 

So  recent  are  some  of  the  smaller  peaks  set  upon  the  lava 


308  THE  ANDES  OF  SOUTHERN  PERU 

plateau  that  forms  the  greater  part  of  the  Maritime  Cordillera, 
that  the  snows  massed  on  their  shadier  slopes  have  not  yet  ef- 
fected any  important  topographic  changes.  The  symmetrical 
peaks  of  this  class  are  in  a  few  cases  so  very  recent  that  they  are 
entirely  uneroded.  Lava  flows  and  beds  of  tuff  appear  to  have 
originated  but  yesterday,  and  shallow  lava-dammed  lakes  retain 
their  original  shore  relations.  In  a  few  places  an  older  topog- 
raphy, glacially  modified,  may  still  be  seen  showing  through  a 
veneer  of  recent  ash  and  cinder  deposits,  clear  evidence  that  the 
loftier  parts  of  the  lava  plateau  were  glaciated  before  the  last 
volcanic  eruption. 

The  asymmetry  of  the  peaks  and  ridges  in  the  Maritime  Cordil- 
lera cannot  be  ascribed  to  the  manner  of  eruption,  since  the  con- 
trast in  declivity  and  form  is  persistently  between  northern  and 
southern  slopes.  Strong  and  persistent  winds  from  a  given  direc- 
tion undoubtedly  influence  the  form  of  volcanoes  to  at  least  a 
perceptible  degree.  In  the  case  in  hand  the  ejectamenta  are 
ashes,  cinders,  and  the  like,  which  are  blown  into  the  air  and  have 
at  least  a  small  component  of  motion  down  the  wind  during  both 
their  ascent  and  descent.  The  prevailing  winds  of  the  high 
plateaus  are,  however,  easterly  and  the  strongest  winds  are  from 
the  west  and  blow  daily,  generally  in  the  late  afternoon.  Both 
wind  directions  are  at  right  angles  to  the  line  of  asymmetry,  and 
we  must,  therefore,  rule  out  the  winds  as  a  factor  in  effecting  the 
slope  contrasts  which  these  mountains  display. 

It  remains  to  be  seen  what  influence  a  covering  of  vegetation 
on  the  nortliorn  slopes  might  have  in  protecting  them  from  ero- 
sion. The  northern  slopes  in  this  latitude  (14°  S.)  receive  a 
nnich  greater  quantity  of  heat  than  the  southern  slopes.  Above 
18,000  feet  (5,490  m.)  snow  occurs  on  llie  shady  southern  slopes, 
but  is  at  least  a  thousand  feet  higher  on  the  northern  slopes.  It 
is  tlierefore  a])sent  from  the  norihorn  side  of  all  but  the  highest 
peaks.  Thus  vegetation  on  the  northern  slopes  is  not  limited  by 
snow.  Bunch  grass — the  characteristic  ichu  of  the  mountain 
shepherds— scattered  spears  of  smaller  grasses,  large  ground 
mosses  called  yarcAa,  and  lichens  extend  1o  1he  snowline.     This 


GLACIAL  FEATURES  309 

vegetation,  however,  is  so  scattered  and  thin  above  17,500  feet 
(5,330  m.)  that  it  exercises  no  retarding  influence  on  the  run-off. 
Far  more  important  is  the  porous  nature  of  the  volcanic  material, 
which  allows  the  rainfall  to  be  absorbed  rapidly  and  to  appear  in 
springs  on  the  lower  slopes,  where  sheets  of  lava  direct  it  to  the 
surface. 

The  asymmetry  of  the  north  and  south  slopes  is  not,  then,  the 
result  of  preglacial  erosion,  of  structural  conditions,  or  of  special 
protection  of  the  northern  slopes  from  erosion.  It  must  be  con- 
cluded, therefore,  that  it  is  due  to  the  only  remaining  factor — 
snow  distribution.  The  southern  slopes  are  snow-clad,  the  north- 
ern are  snow-free — in  harmony  with  the  line  of  asymmetry.  The 
distribution  of  the  snow  is  due  to  the  contrasts  between  shade  and 
sun  temperatures,  which  find  their  best  expression  in  high  alti- 
tudes and  on  single  peaks  of  small  extent.  Frankland's  observa- 
tions with  a  black-bulb  thermometer  in  vacuo  show  an  increase  in 
shade  and  sun  temperatures  contrasts  of  over  40°  between  sea 
level  and  an  elevation  of  10,000  feet.  Violle's  experiments  show 
an  increase  of  26  per  cent  in  the  intensity  of  solar  radiation  be- 
tween 200  feet  and  16,000  feet  elevation.  Many  other  observa- 
tions up  to  16,000  feet  show  a  rapid  increase  in  the  difference  be- 
tween sun  and  shade  temperatures  with  increasing  elevation.  In 
the  region  herein  described  where  the  snowline  is  between  18,000 
and  19,000  feet  (5,490  to  5,790  m.)  these  contrasts  are  still  further 
heightened,  especially  since  the  semi-arid  climate  and  the  conse- 
quent long  duration  of  sunshine  and  low  relative  humidity  afford 
the  fullest  play  to  the  contrasting  forces.  The  coefficient  of  ab- 
sorption of  radiant  energy  by  water  vapor  is  1,900  times  that  of 
air,  hence  the  lower  the  humidity  the  more  the  radiant  energy 
expended  upon  the  exposed  surface  and  the  greater  the  sun  and 
shade  contrasts.  The  effect  of  these  temperature  contrasts  is 
seen  in  a  canting  of  the  snowline  on  individual  volcanoes  amount- 
ing to  1,500  feet  in  extreme  instances.  The  average  may  be  placed 
at  1,000  feet. 

The  minimum  conditions  of  snow  motion  and  the  bearing  of 
the  conclusions  upon  the  formation  of  cirques  have  been  described 


310  THE  ANDES  OF  SOUTHERN  PERU 

in  the  chapters  immediately  preceding.  It  is  concluded  that  snow 
moves  upon  20°  slopes  if  the  snow  is  at  least  forty  feet  deejD, 
and  that  through  its  motion  under  more  favorable  conditions  of 
greater  depth  and  gradient  and  the  indirect  effects  of  border 
melting  there  is  developed  a  hollow  occupied  by  the  snow.  Actual 
ice  is  not  considered  to  be  a  necessary  condition  of  either  move- 
ment or  erosion.  We  may  at  once  accept  the  conclusion  that  the 
invariable  association  of  the  cirques  and  steepened  profiles  with 
snowfields  proves  that  snow  is  the  predominant  modifying  agent. 

An  argument  for  glacial  erosion  based  on  profiles  and  steep 
cirque  walls  in  a  volcanic  region  has  peculiar  appropriateness  in 
view  of  the  well-known  symmetrical  form  of  the  typical  volcano. 
Instead  of  varied  forms  in  a  region  of  complex  structure  long 
eroded  before  the  appearance  of  the  ice,  we  have  here  simple 
forms  which  immediately"  after  their  development  were  occupied 
by  snow.  Ever  since  their  completion  these  cones  have  been 
eroded  by  snoiv  on  one  side  and  by  ivater  on  the  other.  If  snow 
cannot  move  and  if  it  protects  the  surface  it  covers,  then  this  sur- 
face should  be  uneroded.  All  such  surfaces  should  stand  higher 
than  the  slopes  on  the  opposite  aspect  eroded  by  water.  But  these 
assumptions  are  contrary  to  fact.  The  slopes  underneath  the 
snow  are  deeply  recessed;  so  deeply  eroded  indeed,  that  they  are 
bordered  by  steep  cliffs  or  cirque  walls.  The  products  of  erosion 
also  are  to  some  extent  displayed  about  the  border  of  the  snow 
cover.  In  strong  contrast  the  snow-free  slopes  are  so  slightly 
modified  that  little  of  their  original  symmetry  is  lost — only  a  few 
low  hills  and  shallow  valleys  have  been  formed. 

The  measure  of  the  excess  of  snow  erosion  over  water  erosion 
is  therefore  the  difference  between  a  northern  or  water-formed 
and  a  southern  or  snow-formed  profile,  Fig.  200.  This  difference 
is  also  shown  in  Fig.  201  and  from  it  and  the  restored  initial  pro- 
files we  conclude  that  the  rate  of  water  erosion  is  to  that  of  niva- 
tion  as  1:3.  This  ratio  has  been  derived  from  numerous  obser- 
vations on  cones  so  recently  formed  that  the  interlluves  without 
question  are  still  intact. 

Thus  far  onlv  those  volcanoes  have  been  considered  which 


GLACIAL  FEATURES 


311 


have  been  modified  by  nivation.  There  are,  however,  many  vol- 
canoes which  have  been  eroded  by  ice  as  well  as  by  snow  and 
water.  It  will  be  seen  at  once  that  where  a  great  area  of  snow  is 
tributary  to  a  single  valley,  the  snow  becomes  compacted  into 
neve  and  ice,  and  that  it  then  erodes  at  a  much  faster  rate.  Also 
force — plucking — is 


a    new 

called  into  action  when  ice  is 
present,  and  this  greatly  ac- 
celerates the  rate  of  erosion. 
While    it    lies    outside    the 

limits    of   my    subject   to    de-  ^j^       202— Graphic      representation      of 

termine      quantitatively      the""  amount   of   glacial   erosion   during   the   glacial 

p'.riod.     In  the  background  are  mature  slopes 


ratio  between  water  and  ice 
action,  it  is  worth  pointing 
out  that  by  this  method  a 
ratio  much  in  excess  of  1 : 3 
is  determined,  which  even  in 
this  rough  form  is  of  con- 
siderable interest  in  view  of 
the  arguments  based  on  the 
protecting  influence  of  both 
ice  and  snow.  I  have,  in- 
deed, avoided  the  question 
of  ice  erosion  up  to  this 
point  and  limited  myself  to 
those  volcanoes  which  have 
been  modified  by  nivation  only,  since  the  result  is  more  striking 
in  view  of  the  all  but  general  absence  of  data  relating  to  this  form 
of  erosion. 

If  we  now  turn  to  the  valley  profiles  of  the  glaciated  portions 
of  the  Peruvian  Andes,  we  shall  see  the  excess  of  ice  over  water 
erosion  expressed  in  a  manner  equally  convincing.  To  a  thought- 
ful person  it  is  one  of  the  most  remarkable  features  of  any  gla- 
ciated region  that  the  flattest  profiles,  the  marshiest  valley  flats, 
and  the  most  strongly  meandering  stretches  of  the  streams  should 
occur  near  the  heads  of  the  valleys.     The  mountain  shepherds 


surmounted  by  recessed  asymmetrical  peaks. 
The  river  entrenched  itself  below  the  mature 
slopes  before  it  began  to  aggrade,  and,  uhen  ag- 
gradation set  in,  had  cut  its  valley  floor  to 
a'-b'-c.  By  aggradation  the  valley  floor  was 
raised  to  a-b  while  ice  occupied  the  valley  head. 
By  degradation  the  river  has  again  barely 
lowered  its  channel  to  a'-b',  the  ice  has  disap- 
peared, and  the  depression  of  the  profile  repre- 
sents the  amount  of  glacial  erosion. 

a'-b'-c  z=  proghicial  profile. 

a-b-d-c  ■=.  present  profile. 

b'-d-c-b  =  total  ice  erosion  in  the  glacial 
period. 

a-b  =  surface  of  an  alluvial  valley  fill 
due  to  excessive  erosion  at  valley 
head. 

b-b'  =  terminal  moraine. 

d-c  ■=.  cirque  wall. 

e,  e'  e"  =i  asymmetrical  summits. 


312 


THE  ANDES  OF  SOUTHERN  PERU 


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recognize  this  condition  and 
drive  their  flocks  up  from 
the  warmer  valley  into  the 
mountain  recesses,  confi- 
dent that  both  distance 
and  elevation  will  be  off- 
set by  the  extensive  pas- 
tures of  the  finest  icliu 
grass.  Indeed,  to  be  near 
the  grazing  grounds  of 
sheep  and  llamas  which  are 
their  principal  means  of 
subsistence,  the  Indians 
have  built  their  huts  at  the 
extraordinarily  lofty  eleva- 
tions of  16,000  to  17,000  feet. 

An  examination  of  a 
large  number  of  these  val- 
leys and  the  plotting  of 
their  gradients  discloses 
the  striking  fact  that  the 
heads  of  the  valleys  were 
deeply  sunk  into  the  moun- 
tains. It  is  thus  possible 
by  restoring  the  preglacial 
profiles  to  measure  with 
considerable  certainty  the 
excess  of  ice  over  water 
erosion. 

The  results  are  graphi- 
cally expressed  in  Fig.  202. 
It  will  be  seen  that  until 
glacial  conditions  inter- 
vened the  stream  was  flow- 
ing on  a  rock  floor.  During 
the  whole  of  glacial  time  it 


GLACIAL  FEATURES  313 

was  aggrading  its  rock  floor  below  b'  and  forming  a  deep  valley 
fill.  A  return  to  warmer  and  drier  conditions  led  to  the  dis- 
section of  the  fill  and  this  is  now  in  progress.  The  stream  has 
not  yet  reached  its  preglacial  profile,  but  it  has  almost  reached  it. 
We  may,  therefore,  say  that  the  preglacial  valley  profile  below  h' 
fixes  the  position  of  the  present  profile  just  as  surely  as  if  the 
stream  had  been  magically  halted  in  its  work  at  the  beginning  of  the 
period  of  glaciation.  There,  h'-d-c-h  represents  the  amount  of  ice 
erosion.  To  be  sure  the  line  h-c  is  inference,  but  it  is  reasonable  in- 
ference and,  whatever  position  is  assigned  to  it,  it  cannot  be  coin- 
cident with  h'-d,  nor  can  it  be  any^vhere  near  it.  The  break  in  the 
valley  profile  at  h'  is  always  marked  by  a  terminal  moraine,  re- 
gardless of  the  character  of  the  rock.  This  is  not  an  accidental 
but  a  causal  association.  It  proves  the  power  of  the  ice  to  erode. 
In  glacial  times  it  eroded  the  quantity  h-c-d-h'.  This  is  not  an 
excess  of  ice  over  water  erosion,  but  an  absolute  measure  of  ice 
erosion,  since  a'-h'  has  remained  intact.  The  only  possible  error 
arises  from  the  position  assigned  h-c,  and  even  if  we  lower  it  to 
h-c  (for  which  we  have  no  warrant  but  extreme  conservatism)  we 
shall  still  have  left  h'-c'-d-h  as  a  striking  value  for  rock  erosion 
(plucking  and  abrasion)  by  a  valley  glacier. 

A  larger  diagram,  Fig.  203,  represents  in  fuller  detail  the 
topographic  history  of  the  Andes  of  southern  Peru  and  the  rela- 
tive importance  of  glaciation.  The  broad  spurs  with  grass- 
covered  tops  that  end  in  steep  scarps  are  in  wonderful  contrast  to 
the  serrate  profiles  and  truncated  spurs  that  lie  within  the  zone 
of  past  glaciation.  In  the  one  case  we  have  minute  irregularities 
on  a  canyon  wall  of  great  dimensions;  in  the  other,  more  even 
walls  that  define  a  glacial  trough  with  a  flat  floor.  Before  glacia- 
tion on  a  larger  scale  had  set  in  the  right-hand  section  of  the  dia- 
gram had  a  greater  relief.  It  was  a  residual  portion  of  the  moun- 
tain and  therefore  had  greater  height  also.  Glaciers  formed  upon 
it  in  the  Ice  Age  and  glaciation  intensified  the  contrast  between 
it  and  the  left-hand  section ;  not  so  much  by  intensifying  the  relief 
as  by  diversifying  the  topographic  forms. 


J 


i 


^ 


<  pedes  *nd  nage*  fi 


APPENDIX  A 

SURVEY  METHODS  EMPLOYED  IN  THE  CONSTRUCTION  OF 
THE  SEVEN  ACCOMPANYING  TOPOGRAPHIC  SHEETS 

By  Kai  Hendriksen,  Topographer 

The  main  part  of  the  topographical  outfit  consisted  of  (1)  a  4-inch 
theodolite,  Buff  and  Buff,  the  upper  part  detachable,  (2)  an  18  x  24  inch 
plane-table  with  Johnson  tripod  and  micro-meteralidade.  These  instru- 
ments were  courteously  loaned  the  expedition  by  the  U.  S.  Coast  and 
Geodetic  Survey  and  the  U.  S.  Geological  Survey  respectively. 

The  method  of  survey  planned  was  a  combination  of  graphic  triangula- 
tion  and  traverse  with  the  micro-meteralidade.  All  directions  were  plotted 
on  the  plane-table  which,  was  oriented  by  backsight ;  distances  were  deter- 
mined by  the  micro-meteralidade  or  triangulation,  or  both  combined;  and 
elevations  were  obtained  by  vertical  angles.  Finally,  astronomical  observa- 
tions, usually  to  the  sun,  were  taken  at  intervals  of  about  60  miles  for 
latitude  and  azimuth  to  check  the  triangulation.  No  observations  were 
made  for  differences  in  longitude  because  this  would  probably  not  have 
given  any  reliable  result,  considering  the  time  and  instruments  at  our 
disposal.  Because  the  survey  was  to  follow  very  closely  the  seventy-third 
meridian  west  of  Greenwich,  directions  and  distances,  checked  by  latitude 
and  azimuth  observations,  undoubtedly  afforded  far  better  means  of  deter- 
mining the  longitude  than  time  observations.  In  other  words,  the  time 
observations  made  in  connection  with  azimuth  observations  were  not  used 
for  computing  longitudinal  differences.  Absolute  longitude  was  taken 
from  existing  observations  of  principal  places. 

Principal  topographical  points  were  located  by  from  two  to  four  inter- 
sections from  the  triangulation  and  plane-table  stations;  and  elevations 
were  determined  by  vertical  angle  measurements.  Whenever  practicable, 
the  contours  were  sketched  in  the  field;  the  details  of  the  topography 
otherwise  depend  upon  a  great  number  of  photographs  taken  by  Pro- 
fessor Bowman  from  critical  stations  or  other  points  which  it  was  possible 
to  locate  on  the  maps. 


Cross-Section  Map  from  Abancay  to  CamanX  at  the  Pacific  Ocean 

Seven  sheets.  Scale,  1 :  125,000 ;  contour  interval,  200  feet.  Datum  is  mean 
sea  level.  Astronomical  control :  5  latitude  and  5  azimuth  observations  as 
indicated  on  the  accompanying  topographic  sheets. 

315 


316  APPENDIX  A 

On  September  10th,  returning  from  a  reconnaissance  survey  of  the 
Pampaconas  River,  I  joined  Professor  Bowman's  party,  Dr.  Erving  acting 
as  my  assistant.  We  crossed  the  Cordillera  Vilcapampa  and  the  Canyon 
of  the  Apurimac  and  after  a  week's  rest  at  Abancay  started  the 
topographic  work  near  Hacienda  San  Gabriel  south  of  Abancay.  Working 
up  the  deep  valley  of  Lambrama,  observations  for  latitude  and  azimuth 
were  made  midway  betAveen  Hacienda  Matara  and  Caypi. 

On  October  -Ith  we  made  our  camp  in  newly  fallen  snow  surrounded  by 
beautiful  glacial  scenery.  The  next  day  on  the  high  plateau,  we  passed 
sharp-crested  glaciated  peaks;  a  heavy  thunder  and  hail  storm  broke  out 
while  I  occupied  the  station  at  the  pass,  the  storm  continuing  all  the  after- 
noon— a  frequent  occurrence.  The  camp  w^as  made  6  miles  farther  on,  and 
the  next  morning  I  returned  to  finish  the  latter  station.  I  succeeded  in 
sketching  the  detailed  topography  just  south  of  the  pass,  but  shortly  after 
noon,  a  furious  storm  arose  similar  to  the  one  the  day  before,  and  made 
further  topographic  work  impossible;  to  get  connection  farther  on  I 
patiently  kept  my  eye  to  the  eye-piece  for  more  than  an  hour  after  the 
storm  had  started,  and  was  fortunate  to  catch  the  station  ahead  in  a  single 
glimpse.  I  had  a  similar  experience  some  days  later  at  station  16,079, 
Antabamba  Quadrangle,  on  the  rim  of  the  high-level  puna,  the  storm  pre- 
venting all  topographic  work  and  barely  allowing  a  single  moment  in  which 
to  catch  a  dim  sight  of  the  signals  ahead  while  I  kept  my  eye  steadily  at 
the  telescope  to  be  ready  for  a  favorable  break  in  the  heavy  clouds  and  hail. 
At  Antabamba  we  got  a  new  set  of  Indian  carriers,  who  had  orders  to 
accompany  us  to  Cotahuasi,  the  next  sub-prefectura.  Raimondi's  map 
indicates  the  distance  between  the  two  cities  to  be  35  miles,  but  although 
nothing  definite  was  stated,  we  found  out  in  Antabamba  that  the  distance 
was  considerably  longer,  and  moreover  that  the  entire  route  lay  at  a  high 
altitude. 

From  the  second  day  out  of  Antabamba  until  Huaynacotas  was  in  sight 
in  the  Cotahuasi  Canyon,  a  distance  of  50  miles,  the  route  lay  at  an 
altitude  of  from  16,000  to  17,630  feet,  taking  in  5  successive  camps  at  an 
altitude  from  15,500  to  17,000  feet;  12  successive  stations  had  the  following 
altitudes: 

1G,379  feet 

1G,S52     " 

17,104     " 

37,550     " 

17,075     "    — highest  stnlioii  occupied. 

17,008     " 

17,633     " 

10,305     " 

17,030     " 

17,128     " 

10,794      " 

10,200     " 


APPENDIX  A  317 

The  occupation  of  these  high  stations  necessitated  a  great  deal  of 
climbing,  doubly  hard  in  this  rarefied  air,  and  often  on  volcanoes  with  a 
surface  consisting  of  bowlders  and  ash  and  in  the  face  of  violent  hailstorms 
that  made  extremely  difficult  the  task  of  connecting  up  observations  at 
successive  stations. 

At  Cotahuasi  a  new  pack-train  was  organized,  and  on  October  25th  I 
ventured  to  return  alone  to  the  high  altitudes  in  order  to  continue  the 
topography  at  the  station  at  17,633  feet  on  the  summit  of  the  Maritime 
Cordillera.  Dr.  Erving  was  obliged  to  leave  on  October  18th  and  Professor 
Bowman  left  a  week  later  in  order  to  carry  out  his  plans  for  a  physi- 
ographic study  of  the  coast  between  Camana  and  Mollendo.  Philippi 
Angulo,  a  native  of  Taurisma,  a  town  above  Cotahuasi,  acted  as  major- 
domo  on  this  journey.  Knowing  the  trail  and  the  camp  sites,  I  was  able 
to  pick  out  the  stations  ahead  myself,  and  made  good  progress,  returning 
to  Cotahuasi  on  October  29th,  three  or  four  days  earlier  than  planned. 
From  Cotahuasi  to  the  coast  I  had  the  assistance  of  Mr.  AYatkins.  The  most 
trying  part  of  the  last  section  of  high  altitude  country  was  the  great 
Pampa  Colorada,  crowned  by  the  snow-capped  peaks  of  Solimana  and 
Coropuna,  reaching  heights  of  20,730  and  21,703  feet  respectively.  The 
passing  of  this  pampa  took  seven  days  and  we  arrived  at  Chuquibamba  on 
November  9th.  Two  circumstances  made  the  work  on  this  stretch 
peculiarly  difficult — the  scarcity  of  camping  places  and  the  high  tempera- 
ture in  the  middle  of  the  day,  which  heated  the  rarefied  air  to  a  degree 
that  made  long-distance  shots  very  strenuous  work  for  the  eyes.  Although 
our  base  signals  were  stone  piles  higher  than  a  man,  I  was  often  forced  to 
keep  my  eye  to  the  telescope  for  hours  to  catch  a  glimpse  of  the  signals; 
lack  of  time  did  not  allow  me  to  stop  the  telescope  work  in  the  hottest  part 
of  the  day. 

The  top  of  Coropuna  was  intersected  from  the  four  stations: 
16,344,  15,545,  16,168,  and  16,664  feet  elevation,  the  intersections  giving 
a  very  small  triangular  error.  The  elevation  of  Mount  Coropuna 's  high 
peak  as  computed  from  these  4  stations  is : 


21,696  feet 
21,746    " 
21,714     " 
21,657    " 


Mean  elevation  21,703  feet  above  sea  level. 


The  elevation  of  Coropuna  as  derived  from  these  four  stations  has  thus 
a  mean  error  of  18  feet  (method  of  least  squares)  while  the  elevation  of 
each  of  the  four  stations  as  carried  up  from  mean  sea  level  through  25 
stations — vertical  angles  being  observed  in  both  directions — has  an  esti- 


318  APPENDIX  A 

mated  mean  error  of  30  feet.  The  result  of  this  is  a  mean  error  of  35  feet 
in  Coropuna's  elevation  above  mean  sea  level. 

The  latitude  is  15'  31'  00"  S. ;  the  longitude  is  72°  42'  40"  W.  of  Green- 
wich, the  cheeking  of  these  two  determinations  giving  a  result  unexpectedly 
close. 

On  November  11th  azimuth  and  latitude  observations  were  taken  at 
Chuquibamba  and  two  days  later  we  arrived  at  Aplao  in  the  bottom  of  the 
splendid  Majes  Valley.  In  the  northern  part  of  this  valley  I  was  prevented 
from  doing  any  plane-table  work  in  the  afternoons  of  four  successive  days. 
A  strong  gale  set  in  each  noon  raising  a  regular  sandstorm,  that  made 
seeing  almost  impossible,  and  blowing  with  such  a  velocity  that  it  was 
impossible  to  set  up  the  plane-table. 

From  Hacienda  Cantas  to  Camana  w-e  had  to  pass  the  western  desert 
for  a  distance  of  45  miles.  We  were  told  that  on  the  entire  distance  there 
was  only  one  camping  place.  This  was  at  Jaguey  de  Majes,  where  there 
was  a  brook  with  just  enough  water  for  the  animals  but  no  fodder.  Thus 
we  faced  the  necessity  of  carrying  water  for  ten  men  and  fodder  for  14 
animals  in  excess  of  the  usual  cargo;  and  we  were  unable  to  foretell  how 
many  days  the  topography  over  the  hot  desert  would  require. 

Although  plane-table  work  in  the  desert  was  impossible  at  all  except  in 
the  earliest  and  latest  hours  of  the  day,  we  made  regular  progress.  We 
camped  three  nights  at  Jaguey  and  arrived  on  the  fourth  day  at  Las 
Lomas. 

The  next  morning,  on  November  23rd,  at  an  elevation  of  2178  feet  near 
the  crest  of  the  Coast  Range,  we  were  repaid  for  two  months  of  laborious 
work  by  a  glorious  view  of  the  Pacific  Ocean  and  of  the  city  of  Camana  with 
her  olive  gardens  in  the  midst  of  the  desert  sand. 

The  next  day  I  observed  latitude  and  azimuth  at  Camana  and  in  the 
night  my  companion  and  assistant  ]\Ir.  Watkins  and  I  returned  across  the 
desert  to  the  railroad  at  Yitor. 


Conclusions 

The  planned  methods  were  followed  very  closely.  In  two  cases  only 
the  plane-table  had  to  be  oriented  by  the  magnetic  needle,  the  backsights 
not  being  obtainable  because  of  the  impossibility  of  locating  the  last  sta- 
tion, passing  Indians  having  removed  the  signals. 

In  one  case  only  the  distance  between  two  stations  had  to  be  deter- 
mined by  graphic  triangulation  exclusively,  the  base  signals  having  been 
destroyed.  Otherwise  graphic  triangulation  was  used  as  a  check  on 
distances. 

W'rtical  angles  wci'e  always  measurrd  in  both  directions  with  the 
exception  of  tho  above-mentioned  cases. 

Observations   for   .'izimutli    wci-c   alwavs   talccn    to   tho   sun   bofoTO   and 


APPENDIX  A  319 

after  noon.  The  direction  used  in  the  azimuth  observation  was  also  taken 
with  the  prismatic  compass.  The  mean  of  the  magnetic  declination  thus 
found  is:  East  8°  30'  plus. 

Observations  for  latitude  were  taken  to  the  sun  by  the  method  of 
circum-meridian  altitudes,  except  at  the  town  of  Vilcabamba  where  star 
observations  were  taken. 

As  a  matter  of  course,  observations  to  the  sun  are  not  so  exact  as  star 
observations,  especially  in  low  latitudes  where  one  can  expect  to  observe 
the  near  zenith.  However,  working  in  high  altitudes  for  long  periods, 
moving  camp  every  day  and  often  arriving  at  camp  2  to  4  hours  after 
sunset,  I  found  it  essential  to  have  undisturbed  rest  at  night.  It  was 
beyond  my  capacity  to  spend  an  hour  or  two  of  the  night  in  finding  the 
meridian  and  in  making  the  observation.  Furthermore,  the  astronomic 
observations  were  to  check  the  topography  mainly,  the  latter  being  the 
most  exact  method  with  the  outfit  at  hand. 

The  following  table  contains  the  comparisons  between  the  latitude  sta- 
tions as  located  on  the  map  and  by  observation : 

Map  Observation 

Camana  Quadrangle  S 16°  37'  34"         16°  37'  34"  ' 

Coropuna,  station  9,691S 15°  48'  30"  (15°  51'  44") 

Cotahuasi,       "      12,588S 15°  11'  40"  15°  12'  30" 

La  Cumbre,    "     16,852S 14°  28'  10"  14°  29'  46" 

Lambrama,     "       8,341S 13°  43'  18"  13°  43'  14" 

The  other  observations,  with  the  exception  of  the  one  on  the  Coropuna 
Quadrangle,  check  probably  as  well  as  can  be  expected  with  the  small  and 
light  outfit  which  we  used,  and  under  the  exceptionally  hard  conditions  of 
work.  The  observation  on  the  Coropuna  Quadrangle  just  south  of 
Chuquibamba  is,  however,  too  much  out.  An  explanation  for  this  is  that 
the  meridian  zenith  distance  was  1°  23'  12"  only  (in  this  case  the  exact 
formula  was  used  in  computing) .  Of  course,  an  error  or  an  accumulation 
of  errors  might  have  been  made  in  the  distances  taken  by  the  micrometer- 
alidade,  but  the  first  cause  of  error  mentioned  is  the  more  probable,  and 
this  is  indicated  also  by  the  fact  that  the  location  on  the  top  of  Mount 
Coropuna  checks  closely  with  the  one  determined  in  an  entirely  independent 
way  by  the  railroad  engineers. 

For  the  cross-section  map  from  Abancay  to  Camana,  the  following 
statistics  are  desirable : 

*  The  observation  at  Camand  checks  very  closely  with  a  Peruvian  observation  the 
value  of  which  is  S.  16°  37'  00". 


320  APPENDIX  A 

Micrometer   traverse    and    graphic    triangulation,    with    contours,    field    scale 
1 :  90,000. 

Total  time  required,  days 40.5 

Average  distance  per  days  in  miles 7.5 

Average  number  of  plane-table  stations  occupied  per  day 1.5 

Average  area  per  day  in  square  miles 38. 

Located  points  per  square  mile 0.25 

Approximate  elevations  in  excess  of  above,  per  square  mile 0.25 

Highest  station  occupied,  feet  above  sea  level 17,675. 

Highest  point  located,  feet  above  sea  level 21,703. 


APPENDIX   B 

Fossil  Determinations 

A  FEW  fossil  collections  were  gathered  in  order  that  age  determinations 
might  be  made.  With  the  following  identifications  I  have  included  a  few 
fossils  (I  and  II)  collected  by  W.  R.  Rumbold  and  put  into  my  hands  in 
1907.  The  Silurian  is  from  a  Bolivian  locality  south  of  La  Paz  but  in  the 
great  belt  of  shales,  slates,  and  schists  which  forms  one  of  the  oldest  sedi- 
mentary series  in  the  Eastern  Andes  of  Peru  as  well  as  Bolivia.  While 
no  fossils  were  found  in  this  series  in  Peru  the  rocks  are  provisionally 
referred  to  the  Silurian.  Fossil-bearing  Carboniferous  overlies  them  but 
no  other  indication  of  their  age  was  obtained  save  their  general  position  in 
the  belt  of  schists  already  mentioned.  I  am  indebted  to  Professor  Charles 
Schuchert  of  Yale  University  for  the  following  determinations. 

I.    Silurian 

San  Roque  Mine,  southwest  slope  of  Santa  Vela  Cruz,  Canton  Ichocu,  Prov- 
ince Inquisivi,  Bolivia. 

Sent  by  William  R.  Rumbold  in  1907. 

Climacograptus  ? 

PhoUdops  trombetana  Clarke? 

Chonetes  striatellus  (Dalman). 

Atrypa  marginalis  (Dalman)  ? 

Ccelospira  n.  sp. 

Ctenodonta,  2  or  more  species. 

Hyolithes. 

Klcedenia. 

Calymene  ? 

Dalmanites,  a  large  species  with  a  terminal  tail  spine. 

Acidaspis. 
These  fossils  indicate  unmistakably  Silurian  and  probably  Middle  Silurian. 
As  all  are  from  blue-black  shales,  brachiopods  are  the  rarer  fossils,  while  bivalves 
and  trilobites  are  the  common  forms.  The  faunal  aspect  does  not  suggest  relation- 
ship with  that  of  Brazil  as  described  by  J.  M.  Clarke  and  not  at  all  with  that  of 
North  America.  I  believe  this  is  the  first  time  that  Silurian  fossils  have  been 
discovered  in  the  high  Andes. 

II.    Lower  Devonian 

Near  north  end  of  Lake  Titicaca. 

Leptocoelia  flabellites  (Conrad),  very  common. 
Atrypa  reticularis  (Linnaeus)  ? 

321 


322  APPENDIX  B 

This  is  a  part  of  the  well-known  and  widely  distributed  Lower  Devonian  fauna 
of  the  southena  hemisphere. 

III.    Upper  Carboniferous 

All  of  the  Upper  Carboniferous  lots  of  fossils  represent  the  well-known 
South  American  fauna  first  noted  by  d'Orbigny  in  1S42,  and  later  added  to  by 
Orville  Derby.  The  time  repi-esented  is  the  equivalent  of  the  Pennsylvanian  of 
North  America. 

Huascatay  between  Pasaje  and  Huancarama. 
Crinoidal  limestone. 
Trepostomata  Brj^ozoa. 
Pohjpora.    Common. 

Streptorhynchus  hallianus  Derby.    Common. 
Chonetes  glaber  Geinitz.     Rare. 
Productus  humholdii  d'Orb.    Rare. 
"  cora  d'Orb.     Rare. 

"  chandlessii  Derby. 

"  sp.  undet.     Common. 

"  sp.  undet.  " 

Spirifer  condor  d'Orb.    Common. 
Hustedia  mormoni  (Marcou).    Rare. 
Seminula  argentca  (Shepard).       " 
Pampaconas,  Pampaconas  valley  near  Vilcabamba. 
Lophophyllum? 
Rhombopora,  etc. 
Productus. 

Camarophoria.    Common, 
Spirifer  condor  d'Orb. 
Hustedia  mormoni  (Marcou). 
Euomphalus.    Large  form. 
Pongo  de  Mainique.    Extreme  eastern  edge  of  Peruvian  Cordillera. 
Lophophyllum. 
Productus  chandlessii  Derby. 

"  cora  d'Orb. 

Orthotetes  correanus  (Derby). 
Spirifer  condor  d'Orb. 
River  bowlders  and  stones  of  Urubamba  river,  just  beyond  eastern  edge  of 
Cordillera  at  month  of  Ticumpinea  river.     (Detached  and  transported  by  stream 
action  from  the  Upper  Carhnjiiforons  at  Pongo  de  Maini(|ue.) 
Mostly  Trepostomata  Rrj'ozoa. 
Many  Productus  spines. 
Productus  cora  d'Orb. 
dnvuirophnria.     Sninp  as  at  I'ampaconos. 
Productus  sp.  uinicl . 
Cotahuasi  A. 

Lophophylhim. 
Productus  peruvianus  d'Orb. 
"  sp.  undet. 


APPENDIX  B  323 

Camarophoria. 
Pugnax  near  utah  (Marcou). 
Seminula  argentea  (Shepard)  ? 
Cotahuasi  B. 

Productus  cora  d'Orb. 

"  near  semireticulatus  (Martin). 

IV.    Comanchian  or  Lower  Cretaceous 

Near  Chuquibambilla. 

Pecten  near  quadricostatus  Sowerby. 

Undet.  bivalves  and  gastropods. 

The  echinid  Laganumf  colomhianum  d'Orb,    A  clypeasterid. 
This  Lower  Cretaceous  locality  is  evidently  of  the  same  horizon  as  that  of 
Colombia  illustrated  by  d'Orbigny  in  1842  and  described  on  pages  G3-105. 


APPENDIX    C 


KEY  TO  PLACE  NAMES 


Abancay,  toA\Ti,  lat.  12°  35',  Figs.  20,  204. 
Abra  Tocate,   pass,   between  Yavero   and 

Urubamba    valleys,    leaving    latter    at 

Rosalina,  (Fig.  8).    See  also  Fig.  55. 
Anta,  town,  lat.  13°  30',  Fig.  20. 
Antabamba,  town,   lat.   14°   20',   Figs.   20, 

204. 
Aplao,  town,  lat.  16°,  Figs.  20,  204. 
Apurimac,  river,  Fig.  20. 
Arequipa,  town,  lat.  16°  30',  Fig.  66. 
Arica,  town,  northern  Chile,  lat.  18°  30'. 
Arma,   river,   tributary  of  Apurimac,   lat. 

13°  25',  (Fig.  20)  ;  tributary  of  OcoQa, 

lat.  15°  30',  (Fig.  20). 
Arma,  village,  lat.  13°   15',  Fig.  20.     See 

also  Fig.  140. 
Auquibamba,   hacienda,   lat.   13°   40',  Fig. 

204. 

Callao,  towTi,  lat.  12°,  Fig.  66. 

CamanS,  town,  lat.  10°  40',  Figs.  20,  66, 
204. 

Camisea,  river,  tributary  of  Urubamba  en- 
tering from  right,  lat.  11°  15'. 

Camp  13,  lat.  14°  30'. 

Cantas,  hacienda,  lat.  16°  15',  Fig.  204. 

Caraveli,  town,  lat.  16°,  Fig.  06. 

Catacaos,  town,  lat.  5°  30',  Fig.  06. 

Caylloma,  town  and  mines,  lat.  15°  30', 
Fig.  06. 

Caypi,  village,  lat.  13°  45'. 

Central  Ranges,  lat.  14°,  Fig.  20.  See  also 
Fig.  157. 

Crro  Azul,  town,  lat.  13°,  Fig.  GO. 

(liachani,  nit.,  ovt-rlooking  Arcqiii|ia,  lat. 
10°  30',   (Fig.  06). 

Chanpiniayii,  river,  tributary  of  Uru- 
bamba entering  at  Sahuayaco,  q.v. 

Chili,  river,  tributary  of  \ilor  ]{iv<r,  lat. 
10°  30',    (Fig.  GO). 

Cliinche,  hacienda,  Urubamba  Valley 
above  Santa  Ana,  lut.  13",  (Fig.  20). 

Chira,  rivor,  lat.  5°,  Fig.  06. 

Choclococha,  lak.-,  hit.  13°  30',  Figs.  GO,  08. 

Cliofif|n<finirau,  ruiriH,  canyon  of  Apurimac 


above  junction  of  Pachachaca  River,  lat. 

13°  25',   (Fig.  20). 
Choquetira,  village,  lat.   13°   20',   Fig.  20. 

See  also  Fig.  136. 
Chosica,  village,  lat.  12°,  Fig.  66. 
Chuquibamba,  town,  lat.  15°  50',  Figs.  20, 

204. 
Chuquibambilla,  village,  lat.  14°,  Figs.  20, 

204. 
Chuquito,  pass,  Cordillera  Vilcapampa  be- 
tween  Arma    and   Vilcabamba    valleys, 

lat.   13°   10',    (Fig.  20).     See  also  Fig. 

139. 
Coast  Range,  Figs.  60,  204. 
Coehabamba,    city,    Bolivia,    lat.    17°    20', 

long.  66°  20'. 
Colorada,  pampa,  lat.  15°  30',  Fig.  204. 
Colpani,  village,  lower  end  of  Canj'on  of 

Torontoy    (Urubamba   River),    lat.    13° 

10'.    See  Fig.  158. 
Copacavana,  village,  Bolivia,  lat.   16°   10', 

long.  09°   10'. 
Coribeni,  river,  lat.  12°  40',  Fig.  8. 
Coropuna,  mt.,  lat.  15°  30',  Figs.  20,  204. 
Corralpata,  village,  Apurimac  Valley  near 

Incahnasi. 
Cosos,  village,  lat.  1G°,  Fig.  204. 
Cotabambas,  town,  Apurimac  Valley,  lat. 

13°  45',   (Fig.  20). 
Cotahuaai,    town,    lat.    15°    10',   Figs.    20, 

204. 
Ciizco,  city,  lat.  13°  30',  Fig.  20. 

Eciiarali,  hacienda,  on  the  Urubamba 
River  between  Santa  Ana  and  Rosalina, 
lat.  12°  40'.  Sec  inset  map.  Fig.  8, 
and  also  Fig.  54. 

Iliiachiuifia,     hacienda,     Urubamba    River 

above    junction    with    Vilcabamba,    lat. 

13°  10',  (Fig.  20).    See  also  Fig.  158. 
nuad(iuirea,  village,  lat.  14°  15',  Figs.  20, 

201. 
Iliiaipo,  lake,  iioiMh  of  Anta,  lat.    13°   25', 

(Fig.  20). 


324 


APPENDIX  C 


325 


ITuambo,  village,  left  bank  Paehacliaca 
River  between  Huancarama  and  Pasaje, 
lat.  13°  35',   (Fig.  20). 

Huancarama,  town,  lat.  13°  40',  Fig.  20. 

Huancarqui,  village,  lat.  1G°  5',  Fig.  204. 

Huascatay,  village,  left  bank  of  Apurimac 
above  Pasaje,  lat.  13°  30',   (Fig.  20). 

Huaynacotas,  village,  lat.  15°  10',  Fig.  204. 

Huichihua,  village,  lat.  14°  10',  Fig.  204. 

(Tablazo  de)  lea,  plateau,  lat.  14°-15°  30', 

Fig.  66. 
lea,  town,  lat.  14°,  Figs.  66,  G7. 
Incahuasi,  village,  lat.   13°  20',  Fig.  20. 
Iquique,  town,  northern  Chile,  lat.  20°  15'. 
(Pampa  de)    Islay,  south  of  Vitor  River, 

(Fig.  66). 

Jaguey,  village,  Pampa  de  Sihuas,  q.v. 

La    Joya,    pampa,    station    on    Mollendo- 

Puno  R.R.,  16°  40',  (Fig.  66). 
Lambrama,  village,  lat.  12°  50',  Fig.  20. 
Lima,  city,  lat.  12°,  Fig.  66. 

Machu  Picchu,   ruins,  gorge  of  Torontoy, 

q.v.,  lat.  13°   10'. 
Majes,  river.  Fig.  204. 
Manugali,    river,   tributary   of    Urubamba 

entering     from     left     above     Puviriari 

River,  lat.  12°  20',   (Fig.  8). 
Maritime  Cordillera,  Fig.  204. 
Matara,  village,  lat.  14°  20',  Fig.  204. 
(El)  Misti,  mt.,  lat.  16°  30',  Fig.  66. 
Mollendo,  town,  lat.  17°,  Fig.  66. 
Moquegua,  town,  lat.  17°,  Fig.  66. 
Morococha,  mines,  lat.  11°  45',  Fig.  66. 
Mulanquiato,     settlement,     lat.     12°     10', 

Fig.  8. 

Occobamba,  river,  uniting  with  Yanatili, 
q.v. 

Ocona,  river,  lat.  15°-16°  30',  Figs.  20,  66. 

Ollantaytambo,  village,  Urubamba  River 
below  Urubamba  town,  lat.  13°  15', 
(Fig.  20),  and  see  inset  nlap,  Fig.  8. 

Pabellon,  hacienda,  Urubamba  River  above 
Rosalina,    (Fig.  20).     See  also  Fig.  55. 

Pacasmayo,  town,  lat.  7°  30',  Fig.  66. 

Pachatusca  ( Pachatusun ) ,  mt.,  overlook- 
ing Cuzco  to  northeast,  lat.  13°  30'. 

Pachitea,  river,  tributary  of  Ucayali  en- 
tering from  left,  lat.  8°  50'. 


Paita,  town,  lat.  5°,  Fig.  66. 

Pampacolca,  village,  south  of  Coropuna, 
q.v. 

Pampaconas,  river,  known  in  lower  course 
as  Cosireni,  tributary  of  Urubamba 
River,  (Fig.  8).  Source  in  Cordillera 
Vilcapampa  west  of  Vilcabamba. 

Pampas,  river,  tributary  of  Apurimac  en- 
tering from  left,  lat.  13°  20'. 

Panta,  mt.,  Cordillera  Vilcapampa,  north- 
west of  Arma,  lat.  13°  15',  (Fig.  20). 
See  also  Fig.  136. 

Panticalla,  pass,  Urubamba  Valley  above 
Torontoy,  lat.  13°  10'. 

Pasaje,  hacienda  and  ferry,  lat.  13°  30', 
Fig.  20. 

Paucartambo  (Yavero),  river,  q.v. 

Paucartambo,  town,  head  of  Paucartambo 
(Yavero)  River,  lat.  13°  20',  long.  71° 
40'.     Inset  map.  Fig.  8. 

Pichu-Piehu,  mt.,  overlooking  Arequipa, 
lat.  16°,  (Fig.  GO). 

Pilcopata,  river,  tributary  of  Upper  Madre 
de  Dios  east  of  Paucartambo,  lat.   13°. 

Pini-pini,  river,  tributary  of  Upper  Madre 
de  Dios  east  of  Paucartambo,  lat.   13°. 

Pisco,  town,  lat.  14°,  Fig.  06. 

Piura,  river,  lat.  5°-6°,  Fig.  66. 

Piura,  town,  lat.  5°  30',  Fig.  66. 

Pomareni,  river,  lat.  12°,  Fig.  8. 

Pongo  de  Mainique,  rapids,  lat.  12°, 
Fig.  8. 

Pucamoco,  hacienda,  Urubamba  River,  be- 
tween Santa  Ana  and  Rosalina,  (Fig. 
20). 

Puquiura,    village,    lat.    13°    5',    Fig.    20. 
See  also  Fig.  158.     Distinguish  Puqura 
in  Anta  basin  near  Cuzco. 
Puqura,  village,  Anta  basin,  east  of  Anta, 
lat.  13°  30',   (Fig.  20). 

Quilca,  town,  lat.  16°  40',  Fig.  66. 
Quillagua,    village,    northern    Chile,    lat. 
21°  30',  long.  69°  35'. 

Rosalina,  settlement,  lat.  12°  35',  Fig.  8. 
See  also  Fig.  20. 

Sahuayaco,  hacienda,  Urubamba  Valley 
above  Rosalina,  (Fig.  20).  See  also 
Fig.  55. 

Salamanca,  town,  lat.  15°  30',  Fig.  20. 

Salaverry,  town,  lat.  8°,  Fig.  66. 

Salcantay,  mt.,  lat.  13°  20',  Fig.  20. 


326 


APPENDIX  C 


San   Miguel,   bridge,   canyon    of   Torontoy 

near  Machu  Piochu,  lat.  13°  10'. 
Santa  Ana,  hacienda,  lat.  12°  50',  Fig.  20. 
Santa   Ana,    river,    name    applied    to   the 

Urubamba  in  the  region  about  hacienda 

Santa  Ana. 
Santa  Lucia,  mines,  lat.  16°,  Fig.  66. 
Santo  Anato,    hacienda,   La   Sama's  hut, 

12°  35',  Fig.  S. 
Sihuas,  Pampa  de,  lat.  16°  30',  Fig.  204. 
Sillilica,"    Cordillera,     east     of     Iquique, 

northern  Chile. 
Sintulini,     rapids     of     Urubamba     River 

above  junction  of  Pomareni,  lat.  12°  10', 

(Fig.  S). 
Sirialo,  river,  lat.  12°  40',  Fig.  8. 
Soiroccocha,    mt.,    Cordillera    Vilcapampa 

north  of  Arma,  lat.  13°  15',   (Fig.  20). 
Solimana,  mt.,  lat.  15°  20',  Fig.  204. 
Soray,  mt.,  Cordillera  Vilcapampa,  south- 
east   of    Mt.    Salcantay,    lat.    13°    20', 

(Fig.  20). 
Sotospampa,  village,  near  Lambrama,  lat. 

13°  50',    (Fig.  204). 
SuUana,  town,  Chira  River,  lat.  5°,   (Fig. 

66). 

Taurisma,  village,  lat.  15°  10',  Fig.  204. 

Ticumpinea,  river,  tributary  of  Uru- 
bamba entering  from  right  below  Pongo 
de  Mainique,  lat.  11°  50',   (Fig.  8). 

Timpia,  river,  tributary  of  Urubamba  en- 
tering from  right,  lat.  11°  45'. 

Tono,  river,  tributary  of  Upper  Madre  de 
Dios,  east  of  Paueartambo,  lat.  13°. 

Torontoy,  canyon  of  the  Urubamba  be- 
tween the  villages  of  Torontoy  and  Col- 
pani,  lat.  13°  10'-13°  15'. 

Torontoy,    village    at    tlie    head    of    the 


canyon  of  the  same  name,  lat.   13°   15'. 

See  inset  map.  Fig.  8. 
Tumbez,  town,  lat.  4°  30',  Fig.  66. 
Tunari,   Cerro   de,   mt.,  northwest  of   Co- 

chabamba,  q.v. 

Urubamba,  river.  Fig.  20. 

Urubamba,  tovna,  lat.  13°  20',  Fig.  20. 

Vilcabamba,  river,  tributary  of  Urubamba 
River  entering  from  left  above  Santa 
Ana,  lat.  13°,  Fig.  8.    See  also  Fig.  158. 

Vilcabamba,  village,  lat.  13°  5',  Fig.  20. 
Sec  also  Fig.  158. 

Vilcanota,  Cordillera,  southern  Peru. 

Vilcanota,  river,  name  applied  to  Uru- 
bamba above  lat.  of  Cuzeo,  13°  30',  (Fig. 
20). 

Vilcapampa,  Cordillera,  lat.  13°  20',  Fig. 
20. 

Vilque,  town,  southern  Peru,  lat.  15°  50', 
long.  70°   30', 

Vitor,  pampa,  lat.  16°  30',  Fig.  66. 

Vitor,  river.  Fig.  66. 

Yanahuara,  pass,  between  Urubamba   and 

Yanatili  valleys,  lat.  13°  10'. 
Yanatili,  river,  tributary  of  Uru!)aniba  en- 
tering from  right  above  Rosalina,    (Fig. 

20).     Sec  (tlfio  Fig.  55. 
Yavero    (Paueartambo),    river,    tributary 

of  Urubamba  entering  from   right,  lat. 

12°  10',  Fig.  8. 
Yavero,  settlement,  at  junction  of  Yavero 

and    Urubamba     rivers,     lat.     12°     10', 

Fig.  8. 
Yunguyo,    town,    southern    Peru,    hit.    16° 

20',  long.  69°   10'. 
Yuyato,  river,  lat.  12°  5',  Fig.  8. 


INDEX 


Abancay,  32,  62,  64,  78,  92,  93,  181,  189, 
221,  243;   suppressing  a  revolution,  89- 

91;  temperature  curve   (diagr. ),  opp.  p. 

180 
Abancay  basin,  154 
Abancay    to    CamanJl    cross-section    map, 

work,  observation  and  statistics,  315 
Abra  Tocate,  73,  80,  81;   topography  and 

vegetation  from   (ill.),  opp.  p.  19 
Abra  de  Malaga,  276 
Acosta,  205 
Adams,  G.  L,  255 
Agriculture,  74-76,  152 
Aguardiente,  74.    Bee  Brandy 
Alcohol,  5,  6 

Alluvial  fans,  60-63,  70,  270  • 
Alluvial     fill,     270-273;     view     in    Majes 

Valley  (ill.),  opp.  p.  230 
Alpacas,  5,  52 

Alto  de  los  Huesos  (ill.),  opp.  p.  7 
Amazon  basin,  Humboldt's  dream  of  (ton- 
quest,  33-35;  Indian  tribes,  30 
Amazonia,  20,  26 
Ancachs,  171 
Andahuaylas,  89 
Andrews,  A.  C,  295 
Angulo,  Philippi,  317 
Anta,  187,  189,  190 
Anta   basin,   62,    108,    197;    geologj^   250; 

view  looking  north  from  hill  near  Anta 

(ill.),  opp.  p.  184 
Antabamba,   52,   53,  95,  96,  99,    101,   189, 

197,    243,    303,    316;    Governor,    95-99, 

100-101;     Lieutenant    Governor,    96-99, 

101 ;  sketch  section,  243 
Antabamba    Canyon,    view    across     (ill.), 

opp.  p.  106 
Antabamba  Quadrangle,  316,  opp.  p.  282 

(topog.  sheet) 
Antabamba    region,    geologic    sketch    map 

and  section,  245 
Antabamba  Valley,  96 
"Antis,"  39 
Aplao,   106,    115,   116,   181,  226,   231,  255, 

256,  257,  273,  318;   composite  structure 

section       (diagr.),      259;      temperature 

curve  (diagr.),  181 


Aplao  Quadrangle   (topog.  sheet),  opp.  p. 

120 
Appendix  A,  315 
Appendix  B,  321 
Appendix  C,  324 
Apurimac,     51,     57,     60,     94,     153,     154; 

crossing  at   Pasaje    (ills.),   opp.   p.   91; 

regional  diagram   of   canyoned   country, 

58 
Apurimac  Canyon,   189;   cloud  belt    (ill.), 

opp.  p.  150 
Arequipa,     52,     89,     92,     117,    120,     137, 

284 ;    glacial   features   near    ( sketches ) , 

280 
Argentina,  93 
Arica,  130,  132,  198 
Arma,  67,  189,  212-214 
Arrieros,  Pampa  de,  280 
Asymmetrical  peaks   (ill.),  opp.  p.  281 
Asymmetry,  305-313;  cross-section  of  ridge 

(diagr.),      300;       postglacial      volcano 

(diagr.),  306 
Auquibamba,  93 
Avalanches,  290 

Bailey,  S.  I.,  284 

Bandits,  95 

Basins,    60,    154;    regional    diagram,    61; 

climatic  cross-section    (diagr.),  62 
Batholith,  Vilcapampa,   215-224 
Belaunde  brothers,  116 
Bergschrunds,  294-305 
Bingham,  Hiram,  ix,  104,  157 
Block  diagram  of  physiography  of  Andes, 

186 
Boatmen,  Indian,  13 
Bogota,  Cordillera  of,  205 
Bolivia,  93,   176,   190,   \S^,   \»^,  24«,  241, 

249,  322";   snowline,  275-277 
Bolivian  boundary,  68 
Border  valleys  of  the  Eastern  Andes,  68- 

87 
Borneo,  206 

Bowman,  Isaiah,  8,  316 
Brandy,  74,  75,  76,  82-83 
Bravo,  Jos^,  245 
Bumstead,  A.  H.,  ix 


327 


328 


INDEX 


Cacao,  74,  S3 

Cacti,  150;  arboreal  (ill.),  opp.  p.  90 

CalchaquI  Valley,  250 

Callao,  US;  cloudiness  (with  diagr.),  133; 

temperature     (with     diagr.),     126-129; 

wind  roses   (diagrs.),  128 
Camana,  21,  112,  115,  116,  117,   US,  140- 

141,   147,   181,  225,  226,  227,  266,  318; 

coastal  Tertiary,  253,  254 ;  plain  of,  229 ; 

temperature  cur\-e   (diagr.),  181 
Camana   Quadrangle    (topog.   sheet),   opp. 

p.  114 
Camana  Valley,  257 
CamanS-Vitor  region,  117 
Camino  del  Penon,  110 
Camisea,  36 
Camp  13,  100,  180,  181;  temperature  curve 

(diagr.),  180 
Campas,  37 
Canals   for   bringing  water,   59,    60,    155; 

projected.  Maritime  Cordillera  (diagr.), 

118 
Cantas,  115,  116,  226,  253,  257,  273,  318 
Canyon  walls   (ills.),  opp.  p.  218 
Canyoned  country,   regional   diagram,  58; 

valley  climates  (diagr.),  59 
Canyons,  00,  72,  73,  197,  219;  Majcs  River 

(ill.),   opp.   p.   230;    topographic  condi- 
tions before  formation  of  deep  canyons 

in   Maritime   Cordillera    (ill.),   opp.   p. 

184 
Caraveli,     climate     data,     134-136;     wind 

roses   (diagrs.),  136 
Carboniferous  fossils,  323 
Carboniferous      strata,      241-247;      hypo- 

thitical    distribution    of    land    and    sea 
(diagr.),  246 
Cashibos,  37 
CatacaoH,  119 

Cattle  tracks   (ill.),  opp.  p.  226 
Caucho,  29 
Caylloma,  104,  105 
Cay  pi,  316 
Central  Ranges,  asymmetrical  peaks  (ill.), 

opp.  p.  281 ;  glacial  features  with  lateral 
moraines     (ill.),    opp.    p.    269;    glacial 

tojiography     between     Lambraina     and 
Antabamba     (ill.),    opp.    p.    280;    steep 
cirque  walls   (ill),  opp.  p-  2H6 
Cerro  Azul,  118 
Cerro  dc  Tunari,  176 
Chachani,  280,  284 
Chanchamoyo,  77 
Charact<T.     Hce  Human  character 


Chaupimayu  Valley,  77  • 

Chicha,  86 

Chile,  130,  132,  193,  260 
Chili  River,  120 

Chili  Valley,  opp.  p.  7    (ill.),  117 
Chimborazo,  281 
Chinche,  271,  272 

Chira  River,  depth  diagram,  119,  120 
Chirumbia,  12 
Choclococha,  Lake,  120 
Chonta  Campas,  37 
Choqquequirau,  154 

Choquetira,   60,  67,  211;   bowldery  fill  be- 
low, 269;  glacial  features,  206-207 
Choquetira  Valley,  moraine   (ill.),  opp.  p. 

208 
Chosica,     136,    137;     cloudiness     (diagr.), 

138 
Chufio,  57 
Chuntaguirus,  41 
Chuquibamba,  54,  72,   107,   110,   111,   112, 

115,  116,  273,  317-319;  sediments,  258 
Chuquibambilla,    53,    189,    220,    221,    222, 

236,    243;    alluvial    fill     (diagr.),    272; 

Carboniferous,  244;  fossils,  323 
Chuquito  pass,  crossing   (ill.),  opp.  p.  7; 

glacial  trough    (ill.),  opp.  p.  205 
Cirque  walls,  steep   (ill.),  opp.  p.  286 
Cirques,    294-305;    development     (diagr.), 

300;        development,       further       stages 

(diagr.),      301;      mode     of      formation 

(diagr.),  297 
Clarke,  J.  M.,  321 
Clearing  in  forest  (ill.),  opp.  p.  25 
Climate,    coast,    125-147;    eastern    border, 

147-153;   Inter-Andean  valleys,  153-155; 

see  also  Meteorological  records 
Climatic  belts,  121-122;  map,  123 
Climatology,  121-156 
Cliza,  276 
Cloud-banners,  16 
Cloud  belt,  143,  opp.  p.   150    (ill.) 
Cloudiness,     132;     Callao     (with    diagr.), 

133;      (IcHirt      station      near      Caraveli 
(diagrs.),     137;     Machu     Picchu,     100; 

Santa  J.ucia   (diagr.),  169 
Clouds,    Inter  .Andean    Valley,    155;    Santa 

Ana    (ill.),    oi)p.    p.    180;    S.inta    Lucia, 
108;    types  on   eastern   border  nf   Andes 
((liagfH.),  148;  sec  also  Fog 
Coast  Range,  111,  113,   114,  110,  118,  225- 

232;    climate,    122-147;    direction,    207; 

diagram    to    show    progressive    lowering 
of   saturation   temperature   in   a  desert. 


INDEX 


329 


127;  geology,  258;  view  between  Mol- 
lendo  and  Arequipa  in  June  (ill.)>  opp. 
p.  226;  wet  and  dry  seasons  (diagrs.), 
132 

Coastal  belt,  map  of  irrigated  and  irriga- 
ble land,  113 

Coastal  desert,  110-120;  regional  diagram 
of  physical  relations,  112;  see  also 
Deserts 

Coastal  planter,  6 

Coastal  region,  topographic  and  climatic 
provinces   (diagr. ),  125 

Coastal  terraces,  225-232 

Coca,  74,  77,  82-83 

Coca  seed  beds   (ill.),  opp.  p.  74 

Cochabamba,  93;  temperature  (diagrs.  of 
ranges),  insert  opp.  p.  178;  weather 
data,  176-178 

Cochabamba  Indians,  276 

Colombia,  205 

Colorada,  Pampa  de,  114,  317 

Colpani,  72,  215,  216,  222,  223;  from  ice 
to  sugar  cane   (ill.),  opp.  p.  3 

Comanchian  fossils,  323 

Comas,  155 

Compafiia  Gomera  de  Mainique,  29,  31,  32 

Concession  plan,  29 

Conibos,  44 

Contador,  84-85 

Copacavana,  176 

Cordilleras,  4,  6,  20,  197 

Coribeni,  15 

Corn,  57,  59,  62 

Coropuna,  109,  110,  112,  202,  253,  317, 
319;  elevation,  317;  glaciation,  307; 
snowline,  283-285 

Coropuna  expedition,  104 

Coropuna  Quadrangle,  197,  opp.  p.  188 
(topog.  sheet),  319 

Corralpata,  51,  59 

Cosos,  231 

Cotabambas,  78 

Cotahuasi,  4,  5,  52,  54,  60,  97,  101,  103. 
104,  180,  197,  199,  316,  317;  alluvial 
fill,  272;  fossils,  322;  geologic  sketch 
maps  and  cross-section,  247 ;  rug  weaver 
(ill.),  opp.  p.  68;  snowline  above,  282- 
283;  temperature  curve  (diagr.),  180; 
view    (ill.),  opp.  p.  57 

Cotahuasi  Canyon,  247,  248,  316 

Cotahuasi  Quadrangle  (topog.  sheet),  opp. 
p.  192 

Cotahuasi  Valley,  geology,  258 

Cotton,  76,  116,  117 


Crest  lines,  asymmetrical,  305-313 

Cretaceous  formations,  247-251 

Cretaceous  fossils,  323 

Crucero  Alto,  188 

Cuzco,  8,  10,  21,  52,  62,  63,  92,   102,  107, 

193,  197;  railroad  to  Santa  Ana,  69-70; 

snow,  276;  view  (ill.),  opp.  p.  66 
Cuzco  basin,   61,   62,    154,   251;    slopes   at 

outlet  (diagr.),  185 

Deformations.     See  Intrusions 

Derby,  Orville,  322 

Desaguadero  Valley,  193 

Deserts,  cloudiness  (diagrs.),  137;  rain, 
138-140;  sea-breeze  in,  132;  tropical  for- 
est, 36-37;  wind  roses  (diagrs.),  136 

Diagrams.     See  Regional  diagrams 

Dikes,  223 

Drunkenness,  103,  105-106,  108 

Dry  valleys,  114-115 

Dunes,  114,  254;  Majes  Valley,  262-267; 
movement,  132;  superimposed  (diagrs.), 
265 

Duque,  Seiior,  78 

Eastern  Andes,  204-224;  regional  dia- 
gram, 22 

Eastern  border,  climate,  147-153 

Eastern  valley  planter,  3 

Eastern  valleys,  68-87;  climate  cross-sec- 
tion (diagr.),  79 

Echarati,  10,  77,  78,  80,  82;  plantation 
scene  (ill.),  opp.  p.  75 

Ecuador  volcanoes,  281 

Epiphyte  (ill.),  opp.  p.  78 

Erdis,  E.  C,  158 

Erosion,  192-195,  210,  211,  305;  see  also 
Glacial  erosion;  Nivation 

Erving,  Dr.  W.  G.,  13,   101,  316,   317 

Faena  Indians,  75,  83-87 

Feasts  and  fairs,  175-176 

Ferries,  147 

Fig  tree  (ill.),  opp.  p.  75 

Floods,  151 

Fog,  132,  139,  143;  conditions  along  coast 
from  CamanJi  to  Mollendo,  144-145;  see 
also  Clouds 

Forest  dweller,  1 

Forest  Indians.     See  Machigangas 

Forests,  clearing  (ill.),  opp.  p.  25;  dense 
ground  cover,  trees,  epiphytes,  and 
parasites  (ill.),  opp.  p.  155;  moss- 
draped   trees    (ill.),   opp.   p.   24;   moun- 


330 


INDEX 


tain,  148-153;   mule  trail   (ill.),  opp.  p. 

18;   tropical,  near  Pabellon    (ill.),  opp. 

p.  150;  tropical  vegetation  (ill.),  opp.  p. 

18;  type  at  Sahuayaco  (ill.),  opp.  p.  90 
Fossils,    245,    321;    list    of,    by    geologic 

periods  and  localities,  321 
Frankland,  278,  309 
Frost  line,  56-57 

Garua,  132 

Geographical  basis  of  revolutions  and  of 
human  character,  88-109 

Geologic  dates,  195-196;  Majes  Valley, 
258,  261;  west  coast  fault,  248-249 

Geologic  development.  See  Physiographic 
and  geologic  development 

Gilbert,  G.  K.,  300,  302,  305 

Glacial  deposits,  268 

Glacial  erosion.  Central  Andes,  305-313; 
composite  sketch  of  general  conditions, 
312;  graphic  representation  of  amount 
during  glacial  period,  311 

Glacial  features,  274-313;  Arequipa 
(sketches),  280;  Central  Ranges;  lat- 
eral moraines  (ill.),  opp.  p.  209;  eastern 
slopes  of  Cordillera  Vilcapampa  (map), 
210 

Glacial  retreat,  208-214 

Glacial  sculpture,  heart  of  the  Cordillera 
Vilcapampa  (map),  212;  southwestern 
flank  of  Cordillera  Vilcapampa  (map), 
207 

Glacial  topography  between  Lambrama 
and  Antabamba  (ill.),  opp.  p.  280; 
Maritime  Cordillera,  north  of  divide  on 
73d  meridian   (ill.),  opp.  p.  281 

Glacial  trough,  view  near  Chuquito  i)a8s 
(ill.),  opp.  p.  208 

Glaciation,  04,  271;  Sierra  Nevada,  305; 
Vilcapampa,  204-214;  Wosteni  Andes, 
202 

Glaciers,  Panta  Mountain  (ill.),  <i|i|).  p. 
287;  view   (ill.),  opp.  p.  205 

Gomara,  34 

Gonzales,  Sefior,  78 

Government,  bad,  95 

Gran  Pajonnl,  37 

Grnnit*',  215-224;  see  nlno  IntrusionH 

GraHS   (ill.),  opp.  p.   15 1 

Gregory,  .J.  W.,  205 

JIacendddo,  55,  00 
Haciendas,  78,  83,  86 
Tlrinn,  .1.,  120,  17fi,  278 


Hendriksen,  Kai,  98,  315 

Hettner,  205 

Hevea,  29 

Highest  habitations  in  the  world,  52,  96; 

regional  diagram  of,  50;  stone  hut  (ill.), 

opp.  p.  48 
Highland  shepherd,  4 
Highlands,  46 
Hobbs,  ^Y.  H.,  286,  287 
Horses,  66,  opp.  p.  91   (ill.) 
Huadquina,   70,   71,   72,    75,    82,    86,   219; 

hacienda     (ill.),    opp.    p.    73;    terraces, 

272 
Huadquirca,  243 
Huaipo,  Lake,  250,  251 
Iluallaga  basin,  153 
Huambo,  243 
Huancarama,   64,  87,   189,  243,  303;   view 

(ill.),  opp.  p.  106 
Huancarqui,  257 
Huari,  176 
Huascatay,   189,  242,  243;   Carboniferous, 

244;  fossils,  322 
Huasco  basin,  275 
Huaynacotas,    103,    310;    terraced    valley 

slope   (ill.),  opp.  p.  56;  terraced  valley 

slopes   (ill.),  opp.  p.  199 
Ihiichihua,  278;  alluvial  fill  (diagr.),  272; 

(ill.h  opp.  p.  67 
Human    character,    geographic    basis,    88- 

109 
Humboldt,  33-35,  286 
Humboldt  Current,  126,  143 
Huts,  103;  highest  in  Peru    (ill.),  opp.  p. 

48;  shepherds',  47,  48,  52,  55 

lea  Valley,  120;  irrigated  and  irrigable 
land   (diagr.),   118 

Toe  erosion.    See  Glacial  erosion 

Incahuasi,  51,  155,  285 

Incas,J3a,  44,  4(1,  62,  03,  08,  77,   109,   175 

Incliarate,  78 

Indian  boatmen,  13 

Indians,  as  laborers,  26-28,  31-32;  basin 
type,  03-04;  forest,  see  Macliigangas; 
life  and  tastes,  107-108;  mountain,  40- 
07,  101-102;  plateau,  40-41,  44-45,  100, 
100-109;  troo|)H,  90,  91;  wrongs,  14,  102 

Ingomwitnbi,  20(S 

Insti  uint'Tits,  surveying,  315 

Inter-Andean  valleys,  climate,  153-155 

Interment  basin.     See  Basins 

Intrusions,  deformations  north  of  Lam- 
brama    (diagr.),    243;    (leforiiial  ive    ef- 


INDEX 


331 


fects  on  limestone  strata  near  Chuqui- 
bambilla  (diagr.),  221;  lower  Uru- 
bamba  Valley  (geologic  sketch  map), 
237;  overthrust  folds  in  detail  near 
Chuquibambilla  (diagr.),  222;  princi- 
ples, 217-219 

Intrusions,  Vilcapampa,  deformative  ef- 
fects near  Puquiura  (diagr.),  216;  ri'la- 
tion  of  granite  to  schist  near  Colpani 
(with  diagr.),  216 

Iquique,  wind  roses   (diagrs. ),  131 

Irrigation,  72,  76,  80,  82;  coastal  belt 
(map),  113;  coastal  desert,  119-120; 
lea  Valley   (diagr.),  118 

Islay,  Pampa  de,  114 

Italians,  18,  81 

Jagufy,  254,  255,  318 

Jesuits,  68 

Johnson,  W.  D.,  213,  295,  296,  299,  300 

Kenia,  Mt.,  206,  274 
Kerbey,  Major,  8,  10 
Kibo,  206,  274 
Kilimandjaro,  205,  206 
Kinibalu,  206 
Kriiger,  Ilerr,  157 

Labor,  26-28,  31-32,  42-43,  74-75,  83-84 
La  Cumbre  Quadrangle,   197,  202,  opp.  p. 

202   (topog.  sheet) 
La   Joya,    132,    133;    cloudiness    (diagr.), 

134;   temperature  curves    (diagr.),  134; 

wind  roses   (diagrs.),  135 
Lambrama,   90,   92,  285,   316;    camp  near 

(ill.),  opp.  p.  6 
Lambrama     Quadrangle     (topog.     sheet), 

opp.  p.  304 
Lambrama      Valley,      deformation      types 

(diagr.),  243 
Land  and  sea,  Carboniferous  hypothetical 

distribution      compared      with     present 
(diagr.),  246 
Landscape,  183-198 
Lanius,  P.  B.,  13 
La  Paz,  93,  109,  276,  321 
La  Sama,  12,  13,  40 
Las  Lomas,  318 
Lava  flows,  199 
Lava  plateau,  197,  199,  307-308;  regional 

diagram    of     physical     conditions,     55; 
.    summit  above  Cotahuasi    (ill.),  opp.  p. 

204 
Lavas,  volume,  201 


Lima,   92,  93,    118,   137,   138;    cloud,    132, 

143;  temperature,  126 
Limestone,  sketch   to  show  deformed,  243 
Little,  J.  P.,  135,  157 
Llica,  275 

Lower  Cretaceous  fossils,  323 
Lower  Devonian  fossils,  321 

Machigangas,  10,  11,  12,  14,  18,  19,  31, 
36-45,  81;  ornaments  and  fabrics  (ill.), 
opp.  p.  27;  trading  with  (ill.),  opp.  p. 
26 

Machu  Picchu,  72,  220;  weather  data 
(with  diagr.),  158-160 

Madeira-Mamor6  railroad,  33 

Madre  de  Dios,  1,  2,  33  ^ 

Majes  River,  147,  225,  227,  266,  267; 
Canyon    (ill.),  opp.  p.  230 

Majes  Valley,  106,  111,  116,  117,  120,  226, 
227,  229-231,  318;  alluvial  fill,  273;  date 
of    formation,    258,    261;    desert    coast 
(ill.),    opp.    p.    110;     dunes,    262-267; 
erosion  and  uplift,  261 ;  lower  and  upper 
sandstones     (ill.),    opp.    p.    250;     sedi- 
ments, 255;   snowline,  283;   steep  walls 
and    alluvial    fill     (ill.),    opp.    p.    230; 
structural    details    near   Aplao    (sketch 
section),    255;     structural     details    on 
south  wall  near  Cantas  ( sketch  section ) , 
257;     structural     relations     at    Aplao 
(field  sketch),  256;    Tertiary  deposits, 
253-254;  wind,  130;  view  below  Cantas 
(ill.),  opp.   p.    110;   view   down   canyon 
(ill.),  opp.  p.  144 
Malaria,  14,  38 
Maranon,  41,  59 
Marcoy,  79 
Marine  terrace  at  Mollendo   (ill.),  opp.  p. 

226 
Maritime    Cordillera,    52,     199-203,    233; 
asymmetry   of    ridges,    308-309;    glacial 
features,  307;   glacial  topography  north 
of  divide  on  73d  meridian   (ill.),  opp.  p. 
281 ;  pre-volcanic  topography,  200 ;  post- 
glacial  volcano,  asjnnmetrical    (diagr.), 
306;  regional  diagrams,  50,  52;   test  of 
explanation  of   cirques,   303;    volcanoes, 
tuffs,    lava    flows     (ill.),    opp.    p.    204; 
western  border  rocks   (geologic  section), 
257;  see  also  Lava  plateau 
Matara,  99,  316 
Matthes,  F.  E.,  286,  287,  289 
Mature  slopes,  185-193;  between  OUantay- 
tambo    and    Unibamba     (ill.),    opp.    p. 


332 


INDEX 


ISo;  dissected,  north  of  Anta  (ill.), 
opp.  p.  185 

Mawenzi,  206 

Meanders,  16,  17 

Medanos,  114 

Mendoza,  Padre,   11 

Mer  de  Glace,  203 

Meteorological  records,  157-lSl 

Mexican  revolutions,  93 

Middendorf,    143 

Miller,  General,  41,  78,  147 

Minchin,  241 

Misti,  El,  opp.  p.  7    (ill.),  284 

Molina,  Christoval  de,  175 

Mollendo,  93,  105,  117;  cloud  belt,  143; 
cloudiness  (diagr. ),  134;  coastal  ter- 
races, 225;  humidity,  133;  marine  ter- 
race (ill.),  opp.  p.  226;  profile  of 
coastal  terraces  (diagr.),  227;  tem- 
perature curves  (diagr.),  134;  wind 
roses   (diagrs. ),  129 

Mollendo- Arequipa  railroad,  117 

Mollendo  rubber,  32 

Montaiia,   148,  149,   153 

Moquegua,  117;  geologic  relations 
(diagr.),  255 

Moraines,  207,  210-211;  Choquetira  Valley 
(ill.),  opp.  p.  208;  view  (ill.),  opp.  p. 
208 

Morales,  Senor,  11 

Morococha,  temperature  (diagi's.  of 
ranges),  insert  opp.  p.  172;  weather 
data  (with  diagrs.),  171-170 

Morococlia  Mining  Co.,  157,  171 

Morro  de  Arica,  132 

Moss,  large  ground.     See  Yarcla 

Moss-draped  trees  (ill.),  opp.  p.  24 

Mountain-side  trail    (ill.),  opp.  p.  78 

Mountains,  tropical,  as  climate  registers, 
200 

Mulanquiato,  10,  IS,  1!) 

Mule  trail   (ill.),  opp.  p.  18 

Mules,  23,  24,  94,  opp.  p.  91   (ill.) 

N^vC',  286-305 

Nifio,  EI,  137-138 

Nivation,      285-294;      "pocked"      surface 

(ill.),  opp.  p.  286 
NortheuHtorii      border,     (oi»o^'rnpliic      iiiiil 

Btrnctnral  section   (dingr.),  211 

Occolmniba  Valley,  79 

Ocean  curn-ntH  of  adjnnnt  wnt4rH,  121- 
122   (ninp),  123 


Ollantaytambo,     70,     73,     75,     250,     271; 

terraced     valley    floor     (ill.),     opp.     p. 

56 
d'Orbigny,  322 
Oruro,  93 

Pabellon,  80,  82,  opp.  p.  150 

Pacasmaj'o,     Carboniferous     land     plants, 

245 
Pachitea,  37,  38 
Pacific  Ocean  basin,  248 
Paleozoic  strata  (ill.),  opp.  p.  198 
Palma  carmona,  29 
Palmer,  H.  S.,  250 
Paltaybamba,  opp.  p.  74 
Parapacolca,  109 
Pampaconas,    69,   211,   213,   215;    rounded 

slopes   near   Vilcabamba    (ill.),   opp.   p. 

72;    Carboniferous,    244;    fossils,    322; 

snow  action,  291 
Pampaconas  River,  316 
Pampas,  114,  198;  climate  data,  134-136 
Pampas,  river,  189 

Panta,   mt.,   214;   view,   with   glacier   sys- 
tem  (ill.),  opp.  p.  287 
Para  rubber,  32 
Pasaje,  51,  57,  59,  60,  236,  238,  240,  241, 

243;    Carboniferous,    244;    crossing   the 

Apurimac   (ills.),  opp.  p.  91 
Paschinger,  274 
Pastures,   141,   187;   Alpine    (ill.),  opp.  p. 

58 
Paucartanibo,  42,  77 
Paueartainbo  River.     See  Yavero  River 
Payta,  225 
Penek,  A.,  205 
Peonage,  25,  27,  28 
Pereira,  Senor,  10,  18 
Perene,  155 
Physiographic   and    geologic    development, 

2:f;?-273 
Pliysiograpliie  evidence,  value,  193-195 
Physiographic  principles,  217 
I'hysiography,     183-180;     Southern     Peru, 

summary,  197-198 
Pichu-Pichu,  284 
Piedmont  nccuninlatioiis,  260 
Pileopnta,  36 
rifii-pifii,  3(i 

I'isco,   l.'tO;  (^arlioiiiferdUH  land  plaiifw,  217 
I'iura,  119 

Piura  River,  d(|)tli  diagram,  11!»,   120 
I'iura  Valley,  48 
Place  names,  key  to,  325 


INDEX 


333 


Plantations,  86;  see  also  Haciendas 

Planter,  coastal,  G 

Planters,  valley,  3,  75,  76 

Plateau  Indians,  40-41,  44-45,  100,  106- 
109 

Plateaus,  196-197 

Pleistocene  deposits,  267-273 

Pomareni,  19 

Pongo  de  Mainique,  8,  9,  11,  15-20,  40,  71, 
179,  239,  241,  242,  273;  canoe  in  rapid 
above  (ill.)>  opp.  p.  11;  Carboniferous, 
244;  dugout  in  rapids  below  (ill.),  opp. 
p.  2;  fossils,  322;  temperature  curve 
(diagr.),  178;  upper  entrance  (ill.), 
opp.  p.  10;  vegetation,  clearing,  and 
rubber  station   (ill.),  opp.  p.  2 

Poopo,  195 

Potato  field  (ill.),  opp.  p.  67 

Potatoes,  57,  59,  G2 

Potosf,  249 

Precipitation.    See  Rain 

Profiles,  composition  of  slopes  and  pro- 
files (diagr.),  191 

Pucamoco,  78 

Pucapacures,  42 

Puerto  Mainique,  29,  30 

Punas,  6,  197 

Puquiura,  67,  87,  211,  216,  236,  238,  239, 
243,  277;  Carboniferous,  244;  composi- 
tion of  slopes   (ill.),  opp.  p.  198 

Puqura,  250 

Quebradas,  145,  155 
Quechuas,  44,  45,  77,  83 
Quenigo,  285 

Quilca,  105,  117,  226,  266 
Quillabamba,  opp.  p.  74 
Quillagua,  260 

Railroads,  74,  75,  76,  93,  101-102,  149; 
Bolivia,  93;   Cuzco  to  Santa  Ana,  69-70 

Raimondi,  77,  78,  109,  110,  135,  155,  170, 
316 

Rain,  115,  119,  120,  122,  124-125;  coast 
region  seasonal  variation,  131-137; 
eastern  border  of  Andes,  belts  (diagrs.), 
148;  effect  of  heavy,  138-140;  effect  of 
sea-breeze,  131-132;  heaviest,  147-148; 
Morococha  (with  diagrs.),  173-176; 
periodic  variations,  137;  Santa  Lucia 
(with  diagrs.),  164-166;  unequal  dis- 
tribution in  western  Peru,  145-147 

Regional  diagrams,  50;  index  map,  23; 
note  on,  51 


Regions  of  Peru,  1,  7 

Reiss,  205,  208 

Revolutions,  geograpliic  basis,  88-109 

Rhone  glacier,  205 

Rice,  76 

Robledo,  L.  M.,  9,  30,  opp.  p.  78 

Rock  belts,  outline  sketch  along  73d 
meridian,  235 

Rocks,  Maritime  Cordillera,  pampas  and 
Coast  Range  structural  relations 
(sketch  section),  254;  Maritime  Cor- 
dillera, western  border  (geologic  sec- 
tion), 257;  Moquegua,  structural  rela- 
tions (diagr.),  255;  Urubamba  Valley, 
succession   (diagr.),  249 

Rosalina,  8,  9,  10,  11,  37,  42,  71,  73,  80, 
82,   153,  237 

Rubber,  18;  price,  32,  33 

Rubber  forests,  22-35 

Rubber  gatherers,  Italian,  18,  81 

Rubber  plant  (ill.),  opp.  p.  75 

Rubber  trees,  152 

Rueda,  Jos6,  78 

Rug  weaver   (ill.),  opp.  p.  68 

Rumbold,  W.  R.,  321 

Russell,  I.  C,  205      , 

Ruwenzori,  206,  274 

Sacramento,  Pampa  del,  37 

Sahuayaco,    77,    78,    80,    83,    179;    forests 

(ills.),   opp.    p.   90;    temperature   curve 

(diagr.),  178 
Salamanca,    54,    56,    105,    106,    180,    181; 

forest,  285;  temperature  curve   (diagr.), 

180;   terraced  hill  slopes    (ill.),  opp.  p. 

58;  view   (ill.),  opp.  p.  107 
Salaverry,  119 

Salcantay,  64,  72,  opp.  p.  3    (ill.) 
San  Geronimo,  276 
Sand.    See  Dunes 
"Sandy  matico  "   (ill.),  opp.  p.  90 
San  Gabriel,  Hacienda,  316 
Santa    Ana,    69,    72,    78,    79,    80,    82,    93, 

153,      179,     237;      clouds      (ill.),     opp. 

p.     180;     temperature    curve     (diagr.), 

178 
Santa  Ana  Valley,  10,  82 
Santa  Lucia,  temperature  ranges  (diagrs.), 

insert    opp.    p.    162;    unusual    weather 

conditions,  169-170;  weather  data  (with 

diagrs.),  161-171 
Santo  Anato,  40,  42,  82,  179;  temperature 

cun'e   (diagr.),  178 
Schists  and  Silurian  slates,  236-241 


334 


INDEX 


SchruncL     See  Bergschrunds 

Schrundline,  300-305 

Schuchert,  Chas.,  321 

Sea  and  land.    See  Land  and  sea 

Sea-breeze,  129-132 

Shepherd,  highland,  4 

Shepherds,  country  of,  46-67 

Shirineiri,  36,  38 

Sierra  Nevada,  305 

Sierra  Nevada  de  Santa  Marta,  205 

Sievers,  \Y.,  143,  176,  205,  263 

Sihuas,  Pampa  de,  114,  198 

Sillilica,  Cordillera,  190,  260 

Sillilica  Pass,  275 

Silurian  fossils,  321 

Silurian  slates,  236-241 

Sintulini  rapids,  19 

Sirialo,  8,  15 

Slave  raiders,  14 

Slavery,  24,  25 

Slopes,  composition  at  Puquiura  (ill.)> 
opp.  p.  198;  composition  of  slopes  and 
profiles  (diagr.),  191;  smooth  grassy 
(ill.),  opp.  p.  79;  see  also  Mature 
slopes 

Smallpox,  14,  38 

Snow,  212;  drifting,  278;  fields  on  summit 
of  Cordillera  Vilcapampa  (ill.),  opp.  p. 
268 

Snow  erosion.    See  Nivatioii 

Snow  motion,  curve  of  (diagr.),  293;  law 
of  variation,  291 

Snowline,  52,  53,  60,  122,  148,  203,  205- 
200,  274-285;  canting  (with  diagr.), 
279;  determination,  282;  difference  in 
degree  of  canting  (diagr.),  281;  glacial 
period,  282;  view  of  canted,  Cordillera 
Vilcapampa  (ill.),  opp.  p.  280 

Snowstorm,  170 

Soiroccocha,  04,  72,  214;  view  (ill.),  opp. 
p.  154 

Kolimana,  4,  202,  317;  glaciatioii,  .S07 

Soray,  64 

Sotospampa,  243 

South  I'acific  Ocean,  125 

Spanish  Conquest,  02,  03,  77 

Sprnro  (botanint),  153 

Stoinmann,  2-19,  270 

•StroamH,  CoaHt  Range,  145-147;  physiog- 
raphy, 192;  sre  also  Water 

Structure.     See  Rocks 

SUlbel,  209 

Sucre,  93 

Sugar,  73,  74,  75,  70,  82-83,  92 


Sullana,  119 

Survey  methods  employed  in  topographic 
sheets,  315 

Tablazo  de  lea,  198 

Tarai.    See  Urubamba  Valley 

Tarapaca,  Desert  of,  260 

Tarapoto,  153 

Taurisma,  317;  geologic  sketch  map  and 
cross-section,  248 

Taylor,  Capt.  A.,  126,  128 

Temperature,  Abancay  curve  (diagr.), 
opp.  p.  180;  Callao  (with  diagr.),  126- 
129;  Cochabamba,  176-178;  Cocha- 
bamba  (d4agrs.  of  ranges),  insert  opp. 
p.  178;  curves  at  various  points  along 
73d  meridian,  178-181;  La  Joya  curves 
(diagr.),  134;  Mollcndo  curves  (diagr.), 
134;  Morococha,  171-173;  Morococha 
(diagrs.  of  ranges),  insert  opp.  p.  172; 
progressive  lowering  of  saturation,  in  a 
desert  (diagr.),  127;  Santa  Lucia,  161- 
164;  Santa  Lucia  (diagrs.  of  ranges), 
insert  opp.  p.  162 

Tempests,  100-170 

Terraces,  coastal,  225-232;  physical  his- 
tory and  physiograpliic  development 
(with  diagrs.),  228-230;  profile  at  Mol- 
lendo   (diagr.),  227 

Terraces,  hill  slopes  (ill.),  opp.  p.  58 

Terraces,  marine    (ill.),  opp.  p.  226 

Terraces,  valley  (ills.),  opp.  p.  56,  opp. 
p.  57,  opp.  p.  66;  Huaynacotas  (ill.), 
opp.  p.  199 

Tcrral,  130 

Tertiary  deposits,  240,  251-267;  coastal, 
253 

Ticunipiiiea,  36,  38,  251 

Tierra  blanca,  254,  260 

Timber  line,  09,  71,  79,   148 

Timpia,  36,  38,  252;  canoe  at  mouth 
(ill.),  opp.  p.  19 

Titicaca,  101,  170,  195,  321 

Titicaca  i)HHin,  107 

Titicaca-Poop<)  basin,  251 

Tocate.    Bee  Abra  Tocate 

Tola  bush   (ill.),  opp.  p.  0 

Tono,  30 

Topographic  and  climatic  cross-si-ction 
(diagr.) ,  opp.  p.  144 

Topographic  and  structural  swtion  of 
nortiieaHtern  border  of  Andes  (diagr.), 
241 

Topographic    map    of    the    Andes    between 


INDEX 


335 


Abancay  and  the  Pacific  Coast  at  Ca- 
mand,  insert  opp.  p.  312 

Topographic  profiles  across  typical  val- 
leys  (diagrs.),  189 

Topographic  regions,  121-122;  map,  123 

Topographic  sheets,  survey  method  em- 
ployed, 315;  list  of,  with  page  refer- 
ences, xi 

Topographical  outfit,  315 

Torontoy,  10,  70,  71,  72,  82,  158,  220 

Torontoy  Canyon,  272,  opp.  p.  3  (ill.); 
cliflf  (ill.),  opp.  p.  10 

Trail   (mountain-side)    (ill.),  opp.  p.  78 

Transportation,  73-74,  93,  152;  rains  and, 
142 

Trees,  150;  see  also  Forests 

Tucapelle  (ship),  117 

Tucker,  H.  L.,  ix 

Tumbez,  119 

Tunari  peaks,  276 

Ucayali,  42,  44 

Uplift,  recent,  190 

Upper  Carboniferous  fossils,  322 

Urubamba,  1,  41,  42,  62,  187;  village,  70, 
73 

Urubamba  River,  72;  fossils,  322;  physi- 
ographic observations,  252-253;  rapids 
and  canyons,  8-21;  shelter  hut  (ill.), 
opp.  p.  11 

Urubamba  Valley,  72,  153,  238;  alluvial 
fans,  270;  alluvial  fill,  272-273;  below 
Paltaybamba  (ill.),  opp.  p.  74;  canyon 
walls  (ill.),  opp.  p.  218;  dissected  al- 
luvial fans  (sketch),  271;  floor  from 
Tarai  (ill.),  opp.  p.  70;  from  ice  to 
sugar  cane  (ill.),  opp.  p.  3;  geologic 
sketch  map  of  the  lower,  237;  line  of 
unconformity  of  geologic  structure 
(ill.),  opp.  p.  250;  rocks,  250;  rocks, 
succession  (diagr.),  249;  sketch  map,  9; 
slopes  and  alluvial  deposits  between  01- 
lantaytambo  and  Torontoy  (ill.),  opp. 
p.  269;  temperature  curves  (diagrs.), 
178-179;  terraced  valley  slopes  and 
floor  (ill.),  opp.  p.  66;  vegetation,  dis- 
tribution (ill.),  opp.  p.  79;  view  below 
Santa  Ana  (ill.),  opp.  p.  155;  wheat 
and  bread,  71 

Valdivia,  Sefior,  101 
Vallenar,  49 

Valley  climates  in  canyoned  region 
(diagr.),  59 


Valley  planters.    See  Planters 

Valley  profiles,  abnormal,  305-313 

Valleys,  eastern;  see  Border  valleys  of  the 
Eastern  Andes;  see  also  Dry  valleys, 
Inter-Andean  valleys;  topographic  pro- 
files across,  typical  in  Southern  Peru 
(diagrs.),  189 

Vegetation,  141;  belts  (map),  123;  dis- 
tribution in  Urubamba  Valley  (ill.), 
opp.  p.  79 ;  shrubbery,  mixed  with  grass 
(ill.),  opp.  p.  154;  Tocate  pass  (ill.), 
opp.  p.  19;  see  also  Forests 

Vicuiia,  54 

Vilcabaniba,  66;  rounded  slopes  (ill.),  opp. 
p.  72 

Vilcabamba  pueblo,  211,  277,  296 

Vilcabamba  Valley,  189 

Vilcanota  knot,  276 

Vilcanota  Valley,  alluvial  fill,  272 

Vilcapampa,  Cordillera,  15,  16,  22,  51,  53, 
64,  66  67,  197,  204-224,  233;  batholith 
and  topographic  efl"ects,  215-224;  canted 
snowline  (ill.),  opp.  p.  280;  climatic 
barrier,  73;  composite  geologic  section 
(diagr.),  215;  glacial  features,  204-214; 
glaciers,  304;  highest  pass,  crossing 
(ill.),  opp.  p.  7;  regional  diagram,  65; 
regional  diagram  of  the  eastern  aspect, 
68;  schrundline,  302;  snow  movement, 
287-289;  snow  fields  on  summit  (ill.), 
opp.  p.  268;  snow  peaks  (ill.),  opp.  p. 
72;  snowline,  277,  279;  southwestern  as- 
pect (ill.),  opp.  p.  205;  summit  view 
(ill.),  opp.  p.  205 

Vilcapampa  Province,  77 

Vilcapampa  Valley,  bowldery  fill,  269 

Vilque,  176 

Violle,  309 

Virazon,  130 

Vitor,  Pampa  de,  114,  318 

Vitor  River,  92,  117,  226,  266,  267 

Volcanic  country,  199 

Volcanic  flows,  geologic  sketch,  244 

Volcanoes,  glacial  erosion,  311;  post- 
glacial, 306-307;  recessed  southern 
slopes  (ill.),  opp.  p.  287;  snowline,  281; 
typical  form,  310;  views  (ills.),  opp.  p. 
204 

Von  Boeck,  176 

Vulcanism,  199;  see  also  Volcanoes 

Ward,  R.  De  C,  126,  143 
Water,  59,  60,   116,   139;   projected  canal 
from   Atlantic   to    Pacific   slope   of   the 


336 


INDEX 


Maritime  Cordillera  (diagr.),  118; 
streams  of  coastal  desert,  intermittent 
and  perennial,  diagrams  of  depth,  119 

Water  skippers,  17 

Watkins,  Mr.,  317,  318 

Weather.    See  Meteorological  records 

Western  Andes,  199-203 

Whymper,  205 

Wind  belts,  122;  map,  123 

Wind  roses,  Callao  (diagrs.),  128;  Cara- 
veli  (diagrs.),  136;  Iquique  (diagrs.), 
131;  La  Joya  (diagrs.),  135;  Macliu 
Picchu  (diagrs.),  159;  Mollcndo 
(diagrs.),  129;  Santa  Lucia  (diagrs.), 
167;  summer  and  mnter  of  1911-1913 
(diagrs.),  130 

Winds,  114,  115;  directions  at  Machu 
Picchu,    158-159;    geologic    action,    262- 


267;  prevailing,  125;  Sant^T  Lucia 
(with  diagrs.),  166-168;  trade,  122,  124; 
sea-breeze,   129-132 

Wine,  116,  117 

Wolf,  205 

Yanahuara  pass,  170 

Yanatili,  41,  42,  44;  slopes  at  junction 
with  Urubamba  River  (ill.),  opp.  p. 
79 

Yareta   (ill.),  opp.  p.  6 

Yavero,  30,  31,  36,  38,  42,  179;  tempera- 
ture curve   (diagr.),  178 

Yavero  ( Paucartambo )  River,  rubber  sta- 
tion (ill.),  opp.  p.  24 

Yuca,  growing  (ill.),  opp.  p.  75 

Yunguyo,  176 

Yuyato,  36,  38 


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